Reviewed, UniProtKB/Swiss-Prot P08500 (UCRI_RHOCA)

Names and origin

Protein names

Recommended name:
    Ubiquinol-cytochrome c reductase iron-sulfur subunit
    EC=1.10.2.2
Alternative name(s):
    Rieske iron-sulfur protein
      Short name=RISP

Gene names

Name:	petA
Synonyms:	fbcF

Organism

Rhodobacter capsulatus (Rhodopseudomonas capsulata)

Taxonomic identifier

1061 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Alphaproteobacteria › Rhodobacterales › Rhodobacteraceae › Rhodobacter

Protein attributes

Sequence length	191 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is a respiratory chain that generates an electrochemical potential coupled to ATP synthesis.
Catalytic activity	QH2 + 2 ferricytochrome c = Q + 2 ferrocytochrome c + 2 H+.
Cofactor	Binds 1 2Fe-2S cluster per subunit.
Subunit structure	The main subunits of complex b-c1 are: cytochrome b, cytochrome c1 and the Rieske protein.
Subcellular location	Cell membrane; Single-pass membrane protein.
Miscellaneous	The Rieske protein is a high potential 2Fe-2S protein.
Sequence similarities	Contains 1 Rieske domain.
Caution	The sequence reported in Ref.2 was thought to originate from R.sphaeroides but was later shown (Ref.3) to be derived from R.capsulatus.

Ontologies

Keywords
Biological process	Electron transport Transport
Cellular component	Cell membrane Membrane
Domain	Transmembrane
Ligand	2Fe-2S Iron Iron-sulfur Metal-binding
Molecular function	Oxidoreductase
PTM	Disulfide bond
Technical term	3D-structure
Gene Ontology (GO)
Biological process	electron transport chain Inferred from electronic annotation. Source: UniProtKB-KW 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
Molecular function	2 iron, 2 sulfur cluster binding Inferred from electronic annotation. Source: UniProtKB-KW electron carrier activity Inferred from electronic annotation. Source: InterPro iron ion binding Inferred from electronic annotation. Source: UniProtKB-KW ubiquinol-cytochrome-c reductase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 191

191

Ubiquinol-cytochrome c reductase iron-sulfur subunit

PRO_0000127762

Regions

Transmembrane

18 – 35

18

Potential

Domain

94 – 189

96

Rieske

Sites

Metal binding

133

1

Iron-sulfur (2Fe-2S)

Metal binding

135

1

Iron-sulfur (2Fe-2S); via pros nitrogen

Metal binding

153

1

Iron-sulfur (2Fe-2S)

Metal binding

156

1

Iron-sulfur (2Fe-2S); via pros nitrogen

Amino acid modifications

Disulfide bond

138 ↔ 155

Natural variations

Natural variant

48

1

A → S in strain: GA.

Natural variant

114

1

T → S in strain: GA.

Natural variant

116

1

P → A in strain: GA.

Experimental info

Mutagenesis

133

1

C → R or S: Photosynthetically incompetent.

Mutagenesis

135

1

H → L or P: Photosynthetically incompetent.

Mutagenesis

138

1

C → F, R or S: Photosynthetically incompetent.

Mutagenesis

153

1

C → R or S: Photosynthetically incompetent.

Mutagenesis

155

1

C → D, G or S: Photosynthetically incompetent.

Mutagenesis

156

1

H → L, P or F: Photosynthetically incompetent.

Mutagenesis

156

1

H → T or Y: Photosynthetically incompetent.

Mutagenesis

159

1

H → A or S: Photosynthetically competent.

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

191

Helix Strand Turn

Details...

Helix

12 – 37

26

Helix

43 – 45

3

Beta strand

50 – 52

3

Beta strand

63 – 67

5

Beta strand

70 – 75

6

Helix

79 – 86

8

Beta strand

90 – 92

3

Beta strand

101 – 103

3

Helix

110 – 114

5

Beta strand

119 – 121

3

Beta strand

127 – 129

3

Beta strand

134 – 136

3

Beta strand

146 – 148

3

Turn

154 – 156

3

Beta strand

166 – 170

5

Beta strand

179 – 186

8

Beta strand

188 – 190

3

Sequences

	Sequence		Length	Mass (Da)
	P08500-1 [UniParc]. Last modified August 1, 1988. Version 1. Checksum: E7D496405154D5F4	FASTA	191	20,440
	10 20 30 40 50 60 MSHAEDNAGT RRDFLYHATA ATGVVVTGAA VWPLINQMNA SADVKAMASI FVDVSAVEVG 70 80 90 100 110 120 TQLTVKWRGK PVFIRRRDEK DIELARSVPL GALRDTSAEN ANKPGAEATD ENRTLPAFDG 130 140 150 160 170 180 TNTGEWLVML GVCTHLGCVP MGDKSGDFGG WFCPCHGSHY DSAGRIRKGP APRNLDIPVA 190 AFVDETTIKL G

References

[1]	"Primary structure of the bc1 complex of Rhodopseudomonas capsulata. Nucleotide sequence of the pet operon encoding the Rieske cytochrome b, and cytochrome c1 apoproteins." Davidson E., Daldal F. J. Mol. Biol. 195:13-24(1987) [PubMed: 2821268] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: ATCC 23782 / LMG 2373 / NCIB 11773 / SB1003 / St. Louis.
[2]	"Nucleotide sequence and transcription of the fbc operon from Rhodopseudomonas sphaeroides. Evaluation of the deduced amino acid sequences of the FeS protein, cytochrome b and cytochrome c1." Gabellini N., Sebald W. Eur. J. Biochem. 154:569-579(1986) [PubMed: 3004982] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: GA.
[3]	"fbc operon, encoding the Rieske Fe-S protein cytochrome b, and cytochrome c1 apoproteins previously described from Rhodopseudomonas sphaeroides, is from Rhodopseudomonas capsulata." Davidson E., Daldal F. J. Mol. Biol. 195:25-29(1987) [PubMed: 2821272] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-95, SHOWS THAT SEQUENCE DESCRIBED IN PUBMED:3004982 ORIGINATES FROM RHODOBACTER CAPSULATUS.
[4]	"petR, located upstream of the fbcFBC operon encoding the cytochrome bc1 complex, is homologous to bacterial response regulators and necessary for photosynthetic and respiratory growth of Rhodobacter capsulatus." Tokito M.K., Daldal F. Mol. Microbiol. 6:1645-1654(1992) [PubMed: 1323023] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-23. Strain: MT1131.
[5]	"Potential ligands to the [2Fe-2S] Rieske cluster of the cytochrome bc1 complex of Rhodobacter capsulatus probed by site-directed mutagenesis." Davidson E., Ohnishi T., Atta-Asafo-Adjei E., Daldal F. Biochemistry 31:3342-3351(1992) [PubMed: 1313292] [Abstract] Cited for: MUTAGENESIS. Strain: MT0-404.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBLGenBankDDBJ

X05630 Genomic DNA. Translation: CAA29116.1.
M18576 Genomic DNA. Translation: AAA26151.1.
Z12113 Genomic DNA. Translation: CAA78099.1.
X03476 Genomic DNA. Translation: CAA27194.1.

PIR

A29336.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1ZRT	X-ray	3.50	E/R	1-191	[»]

ModBase

Search...

Enzyme and pathway databases

BRENDA

1.10.2.2. 567.

Family and domain databases

InterPro

IPR017941. Rieske_2Fe-2S.
IPR014349. Rieske_Fe-S_prot.
IPR006311. Tat.
IPR017909. Twin_arg_translocation_Tat.
IPR019470. Ubiq_cytC_Rdtase_Fe-S_su_TAT.
IPR006317. Ubiquinol_cyt_c_Rdtase_Fe-S-su.
[Graphical view]

Gene3D

G3DSA:2.102.10.10. Rieske_reg. 1 hit.

PANTHER

PTHR10134. Rieske. 1 hit.

Pfam

PF00355. Rieske. 1 hit.
PF10399. UCR_Fe-S_N. 1 hit.
[Graphical view]

TIGRFAMs

TIGR01416. Rieske_proteo. 1 hit.
TIGR01409. TAT_signal_seq. 1 hit.

PROSITE

PS51296. RIESKE. 1 hit.
PS51318. TAT. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

UCRI_RHOCA

Accession

Primary (citable) accession number: P08500
Secondary accession number(s): P07055

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 1, 1988
Last sequence update:	August 1, 1988
Last modified:	June 16, 2009
This is version 86 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)