Q59297 (CYB6_CHLLT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cytochrome bc complex cytochrome b subunit

Gene names

Name:

petB

Organism

Chlorobium limicola f.sp. thiosulfatophilum

Taxonomic identifier

115852 [NCBI]

Taxonomic lineage

Bacteria › Chlorobi › Chlorobia › Chlorobiales › Chlorobiaceae › Chlorobaculum

Protein attributes

Sequence length	428 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Component of the green S-bacteria bc complex, which consists of the Rieske protein and cytochrome b subunit but appears to lack a cytochrome c1-equivalent. This complex has a comparatively low redox potential.
Cofactor	Binds 2 heme groups non-covalently By similarity.
Subcellular location	Cell membrane; Multi-pass membrane protein Potential.
Miscellaneous	Heme 1 (or BL or b562) is low-potential and absorbs at about 562 nm, and heme 2 (or BH or b566) is high-potential and absorbs at about 566 nm By similarity.
Sequence similarities	Belongs to the cytochrome b family.

Ontologies

Keywords
Biological process	Electron transport Respiratory chain Transport
Cellular component	Cell membrane Membrane
Domain	Transmembrane Transmembrane helix
Ligand	Heme Iron Metal-binding
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	respiratory electron transport chain Inferred from electronic annotation. Source: InterPro transport Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell respiratory chain Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	electron carrier activity Inferred from electronic annotation. Source: InterPro metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW oxidoreductase activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed Ref.1
	Chain	2 – 428	427	Cytochrome bc complex cytochrome b subunit		PRO_0000061916
Regions
	Transmembrane	110 – 130	21	Helical; Potential
	Transmembrane	162 – 182	21	Helical; Potential
	Transmembrane	193 – 213	21	Helical; Potential
	Transmembrane	260 – 280	21	Helical; Potential
	Transmembrane	312 – 331	20	Helical; Potential
	Transmembrane	369 – 389	21	Helical; Potential
	Transmembrane	401 – 421	21	Helical; Potential
Sites
	Metal binding	161	1	Iron 1 (heme b562 axial ligand) By similarity
	Metal binding	175	1	Iron 2 (heme b566 axial ligand) By similarity
	Metal binding	261	1	Iron 1 (heme b562 axial ligand) By similarity
	Metal binding	276	1	Iron 2 (heme b566 axial ligand) By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q59297 [UniParc]. Last modified January 23, 2007. Version 3. Checksum: 83F6EFF0894515A2	FASTA	428	47,477
	10 20 30 40 50 60 MAENTPKPAA GTAPAKPKPA APGAAKPAAP KAARPGAAKP AAKPAAPRAA APSGVYKKPP 70 80 90 100 110 120 VDRPDPNPFK DSKRDAVAGW FQERFYVLNP IIDYLKHKEV PKHALSFWYY FGGLGLFFFV 130 140 150 160 170 180 IQILTGLLLL QYYKPTETDA FASFLFIQGE VPFGWLLRQI HAWSANLMIM MLFIHMFSTF 190 200 210 220 230 240 FMKSYRKPRE LMWVSGFVLL LLSLGFGFTG YLLPWNELAF FATQVGTEVP KVAPGGAFLV 250 260 270 280 290 300 EILRGGPEVG GETLTRMFSL HVVLLPGLVM LVLAAHLTLV QILGTSAPIG YKEAGLIKGY 310 320 330 340 350 360 DKFFPTFLAK DGIGWLIGFA LLIYLAVMFP WEIGVKANPL SPAPLGIKPE WYFWAQFQLL 370 380 390 400 410 420 KDFKFEGGEL LAIILFTIGG VVWLLVPFID RQASEEKKSP IFTIFGILVL AFLLINTYRV YAEYSMLK

References

[1]	"A transcription unit for the Rieske FeS-protein and cytochrome b in Chlorobium limicola." Schuetz M., Zirngibl S., le Coutre J., Buettner M., Xie D.-L., Nelson N., Deutzmann R., Hauska G. Photosyn. Res. 39:163-174(1994) Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 2-25.

Cross-references

Sequence databases
EMBL GenBank DDBJ	X73628 Genomic DNA. Translation: CAA52008.1.
PIR	S38461.
3D structure databases
ProteinModelPortal	Q59297.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
InterPro	IPR016175. Cyt_b/b6. IPR005798. Cyt_b/b6_C. IPR005797. Cyt_b/b6_N. IPR016174. Di-haem_cyt_TM. [Graphical view]
Gene3D	G3DSA:1.20.810.10. Cytochrome_b/b6. 1 hit.
PANTHER	PTHR19271. Cytochrome_b/b6. 1 hit.
Pfam	PF00032. Cytochrom_B_C. 1 hit. PF00033. Cytochrom_B_N. 1 hit. [Graphical view]
SUPFAM	SSF81648. Cytochrome_b/b6_C. 1 hit. SSF81342. Transmembr_di-haem_cytochrome. 1 hit.
PROSITE	PS51003. CYTB_CTER. 1 hit. PS51002. CYTB_NTER. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CYB6_CHLLT

Accession

Primary (citable) accession number: Q59297

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	January 23, 2007
Last modified:	September 21, 2011
This is version 68 of the entry and version 3 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program