Reviewed, UniProtKB/Swiss-Prot P80477 (DHSB_PORPU)

Names and origin

Protein names

Recommended name:
    Succinate dehydrogenase [ubiquinone] iron-sulfur subunit
    EC=1.3.5.1
Alternative name(s):
    Iron-sulfur subunit of complex II
      Short name=Ip

Gene names

Name:	SDH2
Synonyms:	SDHB

Encoded on

Mitochondrion

Organism

Porphyra purpurea

Taxonomic identifier

2787 [NCBI]

Taxonomic lineage

Eukaryota › Rhodophyta › Bangiophyceae › Bangiales › Bangiaceae › Porphyra

Protein attributes

Sequence length	239 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Inferred from homology.

General annotation (Comments)

Function	Iron-sulfur protein (IP) subunit of succinate dehydrogenase (SDH) that is involved in complex II of the mitochondrial electron transport chain and is responsible for transferring electrons from succinate to ubiquinone (coenzyme Q) By similarity.
Catalytic activity	Succinate + ubiquinone = fumarate + ubiquinol.
Cofactor	Binds 1 2Fe-2S cluster By similarity. Binds 1 3Fe-4S cluster By similarity. Binds 1 4Fe-4S cluster By similarity.
Pathway	Carbohydrate metabolism; tricarboxylic acid cycle.
Subunit structure	Component of complex II composed of four subunits: a flavoprotein (FP), an iron-sulfur protein (IP), and a cytochrome b composed of a large and a small subunit By similarity.
Subcellular location	Mitochondrion inner membrane; Peripheral membrane protein; Matrix sideBy similarity.
Sequence similarities	Belongs to the succinate dehydrogenase/fumarate reductase iron-sulfur protein family. Contains 1 2Fe-2S ferredoxin-type domain. Contains 1 4Fe-4S ferredoxin-type domain.

Ontologies

Keywords
Biological process	Electron transport Transport Tricarboxylic acid cycle
Cellular component	Membrane Mitochondrion Mitochondrion inner membrane
Ligand	2Fe-2S 3Fe-4S 4Fe-4S Iron Iron-sulfur Metal-binding
Molecular function	Oxidoreductase
Gene Ontology (GO)
Biological process	electron transport chain Inferred from electronic annotation. Source: UniProtKB-KW transport Inferred from electronic annotation. Source: UniProtKB-KW tricarboxylic acid cycle Inferred from electronic annotation. Source: InterPro
Cellular component	mitochondrial inner membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	2 iron, 2 sulfur cluster binding Inferred from electronic annotation. Source: UniProtKB-KW 3 iron, 4 sulfur cluster binding Inferred from electronic annotation. Source: UniProtKB-KW 4 iron, 4 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 succinate dehydrogenase (ubiquinone) 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 – 239	239	Succinate dehydrogenase [ubiquinone] iron-sulfur subunit		PRO_0000158696
Regions
	Domain	24 – 99	76	2Fe-2S ferredoxin-type
	Domain	142 – 172	31	4Fe-4S ferredoxin-type
Sites
	Metal binding	63	1	Iron-sulfur 1 (2Fe-2S) By similarity
	Metal binding	68	1	Iron-sulfur 1 (2Fe-2S) By similarity
	Metal binding	71	1	Iron-sulfur 1 (2Fe-2S) By similarity
	Metal binding	83	1	Iron-sulfur 1 (2Fe-2S) By similarity
	Metal binding	152	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Metal binding	155	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Metal binding	158	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Metal binding	162	1	Iron-sulfur 3 (3Fe-4S) By similarity
	Metal binding	209	1	Iron-sulfur 3 (3Fe-4S) By similarity
	Metal binding	215	1	Iron-sulfur 3 (3Fe-4S) By similarity
	Metal binding	219	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Binding site	167	1	Ubiquinone; shared with DHSD By similarity

Sequences

	Sequence		Length	Mass (Da)
	P80477-1 [UniParc]. Last modified October 1, 1996. Version 1. Checksum: 5209A3754CAC3E20	FASTA	239	27,301
	10 20 30 40 50 60 MRPRNNNLNL KFIRIYRWTP SNQAEAKFSV HPIHTSNCGP MILDALIKIK DEQDSSLAFR 70 80 90 100 110 120 RSCREGICGS CSMNIDGINT LACLKPIKTN ANIITIYPLP HMYIIKDLVP DLSNFFSQYK 130 140 150 160 170 180 YIKPWLINNV PKKSEYLQSE KDRSELNGIY ECILCACCSA SCPSYWWNHD KYLGPAILLQ 190 200 210 220 230 AYRWLADSRD TNAKERLKLL GGKSKLFKCH TIMNCSRTCP KSLNPGKAIA SIKHSINYS

References

[1]	"Genes encoding the same three subunits of respiratory complex II are present in the mitochondrial DNA of two phylogenetically distant eukaryotes." Burger G., Lang B.F., Reith M., Gray M.W. Proc. Natl. Acad. Sci. U.S.A. 93:2328-2332(1996) [PubMed: 8637872] [Abstract] Cited for: NUCLEOTIDE SEQUENCE.

Cross-references

3D structure databases
HSSP	HSSP built from PDB template 1NEK based on UniProtKB P07014.
ModBase	Search...
Family and domain databases
InterPro	IPR006058. 2Fe2S_fd_BS. IPR001450. 4Fe4S_Fe_S_bd. IPR012675. b-grasp_ferredoxin-like. IPR001041. Ferredoxin. IPR012285. Fum_reductase_C. IPR004489. Succ_DHase/fum_Rdtase_Fe-S. [Graphical view]
Gene3D	G3DSA:3.10.20.30. Ferredoxin_fold. 1 hit. G3DSA:1.10.1060.10. Fum_reductase_C. 1 hit.
Pfam	PF00111. Fer2. 1 hit. [Graphical view]
TIGRFAMs	TIGR00384. dhsB. 1 hit.
PROSITE	PS00197. 2FE2S_FER_1. 1 hit. PS51085. 2FE2S_FER_2. 1 hit. PS00198. 4FE4S_FER_1. 1 hit. PS51379. 4FE4S_FER_2. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

DHSB_PORPU

Accession

Primary (citable) accession number: P80477

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1996
Last sequence update:	October 1, 1996
Last modified:	November 25, 2008
This is version 56 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)