1E5N - JenaLib

Asymmetric Unit (Jmol Viewer)

Asym. Unit - sites (Jmol Viewer)

Biological Unit 1 (Jmol Viewer)

Biol. Unit 1 - sites (Jmol Viewer)

Biological Unit 2 (Jmol Viewer)

Title :   E246C MUTANT OF P FLUORESCENS SUBSP. CELLULOSA XYLANASE A IN COMPLEX WITH XYLOPENTAOSE

Authors :   L. Lo Leggio, J. A. Jenkins, G. W. Harris, R. W. Pickersgill

Date :   27 Jul 00 (Deposition) - 08 Dec 00 (Release) - 30 Jan 13 (Revision)

Method :   X-RAY DIFFRACTION

Resolution :   3.20

Chains :   Asym. Unit : A,B
Biol. Unit 1: A  (1x)
Biol. Unit 2: B  (1x)

Keywords :   Glycosyl Hydrolase, Family 10, Xylan Degradation, Hydrolase (Keyword Search: [Gene Ontology, PubMed, Web (Google)] )

Reference :   L. L. Leggio, J. Jenkins, G. W. Harris, R. W. Pickersgill
X-Ray Crystallographic Study Of Xylopentaose Binding To Pseudomonas Fluorescens Xylanase A.
Proteins V. 41 362 2000
PubMed-ID: 11025547
(for further references see the PDB file header)

Molecule 1 - ENDO-1,4-BETA-XYLANASE A
	Chains	:	A, B
	EC Number	:	3.2.1.8
	Engineered	:	YES
	Expression System	:	ESCHERICHIA COLI
	Expression System Taxid	:	562
	Expression System Vector	:	PET3A
	Expression System Vector Type	:	PLASMID
	Fragment	:	CATALYTIC DOMAIN RESIDUES 264-611
	Mutation	:	YES
	Organism Scientific	:	PSEUDOMONAS FLUORESCENS
	Organism Taxid	:	294
	Other Details	:	TRUNCATED CATALYTIC DOMAIN, AA 264-611
	Synonym	:	XYLANASE A
	Variant	:	SUBSP CELLULOSA

		1	2
Asymmetric Unit	:	A	B
Biological Unit 1 (1x)	:	A
Biological Unit 2 (1x)	:		B

Summary Information (see also Sequences/Alignments below)

Asymmetric Unit (2, 12)

No.	Name	Count	Type	Full Name
1	CA	2	Ligand/Ion	CALCIUM ION
2	XYP	10	Ligand/Ion	BETA-D-XYLOPYRANOSE

Biological Unit 1 (1, 5)

No.	Name	Count	Type	Full Name
1	CA	-1	Ligand/Ion	CALCIUM ION
2	XYP	5	Ligand/Ion	BETA-D-XYLOPYRANOSE

Biological Unit 2 (1, 5)

No.	Name	Count	Type	Full Name
1	CA	-1	Ligand/Ion	CALCIUM ION
2	XYP	5	Ligand/Ion	BETA-D-XYLOPYRANOSE

Asymmetric Unit (10, 10)

No.	Name	Evidence	Residues	Description
01	AC1	SOFTWARE	ASN A:253 , ASP A:256 , ASN A:258 , ASN A:261 , ASP A:262	BINDING SITE FOR RESIDUE CA A 348
02	AC2	SOFTWARE	ASN B:253 , ASP B:256 , ASN B:258 , ASN B:261 , ASP B:262	BINDING SITE FOR RESIDUE CA B 348
03	AC3	SOFTWARE	LYS A:47 , HIS A:79 , TRP A:83 , GLU A:127 , ASP A:134 , PHE A:181 , GLN A:213 , TRP A:305 , TRP A:313 , XYP A:403	BINDING SITE FOR RESIDUES XYP A 401 AND XYP A 402
04	AC4	SOFTWARE	ASP A:134 , PHE A:181 , ASN A:182 , MET A:217 , ARG A:250 , TRP A:313 , XYP A:401 , XYP A:404	BINDING SITE FOR RESIDUES XYP A 402 AND XYP A 403
05	AC5	SOFTWARE	ASN A:182 , GLU A:185 , MET A:217 , TYR A:220 , ARG A:250 , TYR A:255 , XYP A:402 , XYP A:405	BINDING SITE FOR RESIDUES XYP A 403 AND XYP A 404
06	AC6	SOFTWARE	GLU A:185 , TYR A:220 , ASN A:253 , TYR A:255 , ASP A:256 , XYP A:403	BINDING SITE FOR RESIDUES XYP A 404 AND XYP A 405
07	AC7	SOFTWARE	LYS B:47 , HIS B:79 , TRP B:83 , GLU B:127 , ASP B:134 , PHE B:181 , GLN B:213 , TRP B:305 , TRP B:313 , XYP B:403	BINDING SITE FOR RESIDUES XYP B 401 AND XYP B 402
08	AC8	SOFTWARE	ASP B:134 , PHE B:181 , ASN B:182 , MET B:217 , ARG B:250 , TRP B:313 , XYP B:401 , XYP B:404	BINDING SITE FOR RESIDUES XYP B 402 AND XYP B 403
09	AC9	SOFTWARE	ASN B:182 , GLU B:185 , MET B:217 , TYR B:220 , ARG B:250 , TYR B:255 , XYP B:402 , XYP B:405	BINDING SITE FOR RESIDUES XYP B 403 AND XYP B 404
10	BC1	SOFTWARE	SER A:27 , GLU B:185 , TYR B:220 , ASN B:253 , TYR B:255 , ASP B:256 , XYP B:403	BINDING SITE FOR RESIDUES XYP B 404 AND XYP B 405

Asymmetric Unit

No.	Residues
1	A:269	-	A:273
2	B:269	-	B:273

Asymmetric Unit

No.	Residues
1	His A:79	-	Ala A:80
2	Tyr A:220	-	Pro A:221
3	His B:79	-	Ala B:80
4	Tyr B:220	-	Pro B:221

(no "SAP(SNP)/Variant" information available for 1E5N)

Asymmetric Unit (2, 4)

	PROSITE			UniProtKB		PDB
No.	ID	AC	Description	ID	Location	Count	Location
1	GH10_2	PS51760	Glycosyl hydrolases family 10 (GH10) domain profile.	XYNA_CELJU	281-607	2	A:17-343 B:17-343
2	GH10_1	PS00591	Glycosyl hydrolases family 10 (GH10) active site.	XYNA_CELJU	503-513	2	A:239-249 B:239-249

Biological Unit 1 (2, 2)

	PROSITE			UniProtKB		PDB
No.	ID	AC	Description	ID	Location	Count	Location
1	GH10_2	PS51760	Glycosyl hydrolases family 10 (GH10) domain profile.	XYNA_CELJU	281-607	1	A:17-343 -
2	GH10_1	PS00591	Glycosyl hydrolases family 10 (GH10) active site.	XYNA_CELJU	503-513	1	A:239-249 -

Biological Unit 2 (2, 2)

	PROSITE			UniProtKB		PDB
No.	ID	AC	Description	ID	Location	Count	Location
1	GH10_2	PS51760	Glycosyl hydrolases family 10 (GH10) domain profile.	XYNA_CELJU	281-607	1	- B:17-343
2	GH10_1	PS00591	Glycosyl hydrolases family 10 (GH10) active site.	XYNA_CELJU	503-513	1	- B:239-249

(no "Exon" information available for 1E5N)

Asymmetric Unit

Reformat:	Number of residues per line = ('0' or empty: single-line sequence representation)
	Number of residues per labelling interval =
	UniProt sequence: complete aligned part

Show mapping:	SCOP domains	CATH domains	Pfam domains	Secondary structure (by author)
	SAPs(SNPs)	PROSITE motifs	Exons
	(details for a mapped element are shown in a popup box when the mouse pointer rests over it)

Chain A from PDB  Type:PROTEIN  Length:346
 aligned with XYNA_CELJU | P14768 from UniProtKB/Swiss-Prot  Length:611

    Alignment length:346
                                   274       284       294       304       314       324       334       344       354       364       374       384       394       404       414       424       434       444       454       464       474       484       494       504       514       524       534       544       554       564       574       584       594       604      
           XYNA_CELJU   265 GLASLADFPIGVAVAASGGNADIFTSSARQNIVRAEFNQITAENIMKMSYMYSGSNFSFTNSDRLVSWAAQNGQTVHGHALVWHPSYQLPNWASDSNANFRQDFARHIDTVAAHFAGQVKSWDVVNEALFDSADDPDGRGSANGYRQSVFYRQFGGPEYIDEAFRRARAADPTAELYYNDFNTEENGAKTTALVNLVQRLLNNGVPIDGVGFQMHVMNDYPSIANIRQAMQKIVALSPTLKIKITELDVRLNNPYDGNSSNDYTNRNDCAVSCAGLDRQKARYKEIVQAYLEVVPPGRRGGITVWGIADPDSWLYTHQNLPDWPLLFNDNLQPKPAYQGVVEALSG 610
               SCOP domains d1e5na_ A: Xylanase A, catalytic core                                                                                                                                                                                                                                                                                                                      SCOP domains
               CATH domains 1e5nA00 A:1-346 Glycosidases                                                                                                                                                                                                                                                                                                                               CATH domains
               Pfam domains ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Pfam domains
         Sec.struct. author hhhhhh...eeeee...........hhhhhhhhhhhh.eeee....hhhh........hhhhhhhhhhhhhh..eee.......hhhhh.........hhhhhhhhhhhhhhhhh.....eeeeee.....................hhhhhhhh.hhhhhhhhhhhhhhh...eeeeee......hhhhhhhhhhhhhhhhh.....eeee..eee....hhhhhhhhhhhhhhh....eeee...eee......................hhhhhhhhhhhhhhhhhhhhhh....eeeeee....hhhh.....................hhhhhhhhhhhh. Sec.struct. author
                 SAPs(SNPs) ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- SAPs(SNPs)
                PROSITE (1) ----------------GH10_2  PDB: A:17-343 UniProt: 281-607                                                                                                                                                                                                                                                                                                 --- PROSITE (1)
                PROSITE (2) ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------GH10_1     ------------------------------------------------------------------------------------------------- PROSITE (2)
                 Transcript ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Transcript
                 1e5n A   1 GLASLADFPIGVAVAASGGNADIFTSSARQNIVRAEFNQITAENIMKMSYMYSGSNFSFTNSDRLVSWAAQNGQTVHGHALVWHPSYQLPNWASDSNANFRQDFARHIDTVAAHFAGQVKSWDVVNEALFDSADDPDGRGSANGYRQSVFYRQFGGPEYIDEAFRRARAADPTAELYYNDFNTEENGAKTTALVNLVQRLLNNGVPIDGVGFQMHVMNDYPSIANIRQAMQKIVALSPTLKIKITCLDVRLNNPYDGNSSNDYTNRNDCAVSCAGLDRQKARYKEIVQAYLEVVPPGRRGGITVWGIADPDSWLYTHQNLPDWPLLFNDNLQPKPAYQGVVEALSG 346
                                    10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160       170       180       190       200       210       220       230       240       250       260       270       280       290       300       310       320       330       340

Chain B from PDB  Type:PROTEIN  Length:346
 aligned with XYNA_CELJU | P14768 from UniProtKB/Swiss-Prot  Length:611

    Alignment length:346
                                   274       284       294       304       314       324       334       344       354       364       374       384       394       404       414       424       434       444       454       464       474       484       494       504       514       524       534       544       554       564       574       584       594       604      
           XYNA_CELJU   265 GLASLADFPIGVAVAASGGNADIFTSSARQNIVRAEFNQITAENIMKMSYMYSGSNFSFTNSDRLVSWAAQNGQTVHGHALVWHPSYQLPNWASDSNANFRQDFARHIDTVAAHFAGQVKSWDVVNEALFDSADDPDGRGSANGYRQSVFYRQFGGPEYIDEAFRRARAADPTAELYYNDFNTEENGAKTTALVNLVQRLLNNGVPIDGVGFQMHVMNDYPSIANIRQAMQKIVALSPTLKIKITELDVRLNNPYDGNSSNDYTNRNDCAVSCAGLDRQKARYKEIVQAYLEVVPPGRRGGITVWGIADPDSWLYTHQNLPDWPLLFNDNLQPKPAYQGVVEALSG 610
               SCOP domains d1e5nb_ B: Xylanase A, catalytic core                                                                                                                                                                                                                                                                                                                      SCOP domains
               CATH domains 1e5nB00 B:1-346 Glycosidases                                                                                                                                                                                                                                                                                                                               CATH domains
               Pfam domains ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Pfam domains
         Sec.struct. author hhhhhh...eeeee...........hhhhhhhhhhhh.eeee....hhhh........hhhhhhhhhhhhhh..eee.......hhhhh.........hhhhhhhhhhhhhhhhh.....eeeeee.....................hhhhhhhh.hhhhhhhhhhhhhhh...eeeeee......hhhhhhhhhhhhhhhhh.....eeee..eee....hhhhhhhhhhhhhhh....eeee...eee......................hhhhhhhhhhhhhhhhhhhhhh....eeeeee....hhhh.....................hhhhhhhhhhhh. Sec.struct. author
                 SAPs(SNPs) ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- SAPs(SNPs)
                PROSITE (1) ----------------GH10_2  PDB: B:17-343 UniProt: 281-607                                                                                                                                                                                                                                                                                                 --- PROSITE (1)
                PROSITE (2) ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------GH10_1     ------------------------------------------------------------------------------------------------- PROSITE (2)
                 Transcript ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Transcript
                 1e5n B   1 GLASLADFPIGVAVAASGGNADIFTSSARQNIVRAEFNQITAENIMKMSYMYSGSNFSFTNSDRLVSWAAQNGQTVHGHALVWHPSYQLPNWASDSNANFRQDFARHIDTVAAHFAGQVKSWDVVNEALFDSADDPDGRGSANGYRQSVFYRQFGGPEYIDEAFRRARAADPTAELYYNDFNTEENGAKTTALVNLVQRLLNNGVPIDGVGFQMHVMNDYPSIANIRQAMQKIVALSPTLKIKITCLDVRLNNPYDGNSSNDYTNRNDCAVSCAGLDRQKARYKEIVQAYLEVVPPGRRGGITVWGIADPDSWLYTHQNLPDWPLLFNDNLQPKPAYQGVVEALSG 346
                                    10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160       170       180       190       200       210       220       230       240       250       260       270       280       290       300       310       320       330       340

Legend:		→ Mismatch	(orange background)
	-	→ Gap	(green background, '-', border residues have a numbering label)
		→ Modified Residue	(blue background, lower-case, 'x' indicates undefined single-letter code, labelled with number + name)
	x	→ Chemical Group	(purple background, 'x', labelled with number + name, e.g. ACE or NH2)
	extra numbering lines below/above indicate numbering irregularities and modified residue names etc., number ends below/above '\|'

Asymmetric Unit

Classes(

)

Folds(

)

Superfamilies( (-)

)

Families(

)

Protein Domains( (-)

)

Organisms( (-)

)

Class: Alpha and beta proteins (a/b) (23833)

Fold: TIM beta/alpha-barrel (3956)

Superfamily: (Trans)glycosidases (1191)

Family: beta-glycanases (284)

Protein domain: Xylanase A, catalytic core (61)

Pseudomonas fluorescens [TaxId: 294] (7)

1a	d1e5na_	A:
1b	d1e5nb_	B:

Asymmetric Unit

Classes(

)

Architectures( (-)

)

Topologies( (-)

)

Homologous Superfamilies( (-)

)

Organisms( (-)

)

Class: Alpha Beta (26913)

Architecture: Alpha-Beta Barrel (2994)

Topology: TIM Barrel (2806)

Homologous Superfamily: Glycosidases (843)

Pseudomonas fluorescens. Organism_taxid: 294. Variant: subsp cellulosa. (1)

1a	1e5nA00	A:1-346
1b	1e5nB00	B:1-346

(no "Pfam Domain" information available for 1E5N)

Asymmetric Unit(hide GO term definitions)

Chain A,B (XYNA_CELJU | P14768)

molecular function
	GO:0030246	carbohydrate binding	Interacting selectively and non-covalently with any carbohydrate, which includes monosaccharides, oligosaccharides and polysaccharides as well as substances derived from monosaccharides by reduction of the carbonyl group (alditols), by oxidation of one or more hydroxy groups to afford the corresponding aldehydes, ketones, or carboxylic acids, or by replacement of one or more hydroxy group(s) by a hydrogen atom. Cyclitols are generally not regarded as carbohydrates.
	GO:0030248	cellulose binding	Interacting selectively and non-covalently with cellulose.
	GO:0031176	endo-1,4-beta-xylanase activity	Catalysis of the endohydrolysis of (1->4)-beta-D-xylosidic linkages in xylans.
	GO:0016787	hydrolase activity	Catalysis of the hydrolysis of various bonds, e.g. C-O, C-N, C-C, phosphoric anhydride bonds, etc. Hydrolase is the systematic name for any enzyme of EC class 3.
	GO:0016798	hydrolase activity, acting on glycosyl bonds	Catalysis of the hydrolysis of any glycosyl bond.
	GO:0004553	hydrolase activity, hydrolyzing O-glycosyl compounds	Catalysis of the hydrolysis of any O-glycosyl bond.
	GO:0030247	polysaccharide binding	Interacting selectively and non-covalently with any polysaccharide, a polymer of many (typically more than 10) monosaccharide residues linked glycosidically.
biological process
	GO:0005975	carbohydrate metabolic process	The chemical reactions and pathways involving carbohydrates, any of a group of organic compounds based of the general formula Cx(H2O)y. Includes the formation of carbohydrate derivatives by the addition of a carbohydrate residue to another molecule.
	GO:0008152	metabolic process	The chemical reactions and pathways, including anabolism and catabolism, by which living organisms transform chemical substances. Metabolic processes typically transform small molecules, but also include macromolecular processes such as DNA repair and replication, and protein synthesis and degradation.
	GO:0000272	polysaccharide catabolic process	The chemical reactions and pathways resulting in the breakdown of a polysaccharide, a polymer of many (typically more than 10) monosaccharide residues linked glycosidically.
	GO:0045493	xylan catabolic process	The chemical reactions and pathways resulting in the breakdown of xylan, a polymer containing a beta-1,4-linked D-xylose backbone.

Asymmetric Unit
	Complete Structure
		Jena3D(integrated viewing of ligand, site, SAP, PROSITE, SCOP information)
		WebMol \| AstexViewer[tm]@PDBe (Java Applets, require no local installation except for Java; loading may be slow)
		STRAP (Java WebStart application, automatic local installation, requires Java; full application with system access!)
		RasMol (require local installation)
		Molscript (VRML) (requires installation of a VRML viewer; select preferred view via VRML and generate a mono or stereo PDF format file)

	Ligands, Modified Residues, Ions
		CA	[ RasMol \| Jena3D ]	+environment [ RasMol \| Jena3D ]
		XYP	[ RasMol \| Jena3D ]	+environment [ RasMol \| Jena3D ]

	Sites
		AC1	[ RasMol ]	+environment [ RasMol ]
		AC2	[ RasMol ]	+environment [ RasMol ]
		AC3	[ RasMol ]	+environment [ RasMol ]
		AC4	[ RasMol ]	+environment [ RasMol ]
		AC5	[ RasMol ]	+environment [ RasMol ]
		AC6	[ RasMol ]	+environment [ RasMol ]
		AC7	[ RasMol ]	+environment [ RasMol ]
		AC8	[ RasMol ]	+environment [ RasMol ]
		AC9	[ RasMol ]	+environment [ RasMol ]
		BC1	[ RasMol ]	+environment [ RasMol ]

	Cis Peptide Bonds
		His A:79 - Ala A:80	[ RasMol ]
		His B:79 - Ala B:80	[ RasMol ]
		Tyr A:220 - Pro A:221	[ RasMol ]
		Tyr B:220 - Pro B:221	[ RasMol ]

Biological Units
	Complete Structure
		Biological Unit 1	[ Jena3D ]
		Biological Unit 2	[ Jena3D ]

Jmol
	protein: cartoon or spacefill or dots and stick; nucleic acid: cartoon and stick; ligands: spacefill; active site: stick [ Asym. Unit PNG format \| Asym. Unit - sites PNG format \| Biol. Unit 1 PNG format \| Biol. Unit 1 - sites PNG format \| Biol. Unit 2 PNG format ](automatic orientation, automatically generated)
Molscript
	protein, nucleic acid: cartoon; ligands: spacefill; active site: ball and stick [ mono PDF format \| stereo PDF format ](default orientation, automatically generated)

Access by PDB/NDB ID
	1e5n
		Family and Domain Information	:	ProDom \| SYSTERS
		General Structural Information	:	GlycoscienceDB \| MMDB \| NDB \| OCA \| PDB \| PDBe \| PDBj \| PDBsum \| PDBWiki \| PQS \| PROTEOPEDIA
		Orientation in Membranes	:	OPM
		Protein Surface	:	SURFACE
		Secondary Structure	:	DSSP (structure derived) \| HSSP (homology derived)
		Structural Genomics	:	GeneCensus
		Structural Neighbours	:	CE \| VAST
		Structure Classification	:	CATH \| Dali \| SCOP
		Validation and Original Data	:	BMRB Data View \| BMRB Restraints Grid \| EDS \| PROCHECK \| RECOORD \| WHAT_CHECK

Access by UniProt ID/Accession number
	XYNA_CELJU \| P14768
		Comparative Protein Structure Models	:	ModBase
		Genomic Information	:	Ensembl
		Protein-protein Interaction	:	DIP
		Sequence, Family and Domain Information	:	InterPro \| Pfam \| SMART \| UniProtKB/SwissProt

Access by Enzyme Classificator (EC Number)
	3.2.1.8
		General Enzyme Information	:	BRENDA \| EC-PDB \| Enzyme \| IntEnz
		Pathway	:	KEGG \| MetaCyc

Access by Disease Identifier (MIM ID)
	(no 'MIM ID' available)
		Disease Information	:	OMIM

Access by GenAge ID
	(no 'GenAge ID' available)
		Age Related Information	:	GenAge

Access by PDB/NDB ID
		Domain Information	:	XDom
		Interatomic Contacts of Structural Units	:	CSU
		Ligand-protein Contacts	:	LPC
		Protein Cavities	:	castP
		Sequence and Secondary Structure	:	PDBCartoon
		Structure Alignment	:	STRAP(Java WebStart application, automatic local installation, requires Java; full application with system access!)
		Structure and Sequence Browser	:	STING

Access by UniProt ID/Accession number
	XYNA_CELJU \| P14768
		Protein Disorder Prediction	:	DisEMBL \| FoldIndex \| GLOBPLOT (for more information see DisProt)

UniProtKB/Swiss-Prot
	XYNA_CELJU \| P14768	:	1clx 1e8r 1qld 1w2p 1w2v 1w32 1w3h 1xys

1clx	CATALYTIC CORE OF XYLANASE A
1qld	SOLUTION STRUCTURE OF TYPE X CBM
1xys	CATALYTIC CORE OF XYLANASE A E246C MUTANT

Description

Compounds

Structural Features

Chains, Units

Ligands, Modified Residues, Ions (2, 12)

Sites (10, 10)

SS Bonds (2, 2)

Cis Peptide Bonds (4, 4)

Sequence-Structure Mapping

SAPs(SNPs)/Variants (0, 0)

PROSITE Motifs (2, 4)

Exons (0, 0)

Sequences/Alignments

Classification and Annotation

SCOP Domains (1, 2)

CATH Domains (1, 2)

Pfam Domains (0, 0)

Gene Ontology (11, 11)

Visualization

Interactive Views

Still Images

Databases and Analysis Tools

Databases

Analysis Tools

Related Entries

Entries Sharing at Least One Protein Chain (UniProt ID)

Related Entries Specified in the PDB File