Reviewed, UniProtKB/Swiss-Prot Q6L372 (CYB6_SACHY)

Names and origin

Protein names

Recommended name:
    Cytochrome b6

Gene names

Name:	petB
ORF Names:	PS155

Encoded on

Plastid; Chloroplast

Organism

Saccharum hybrid (Sugarcane)

Taxonomic identifier

15819 [NCBI]

Taxonomic lineage

Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › Liliopsida › Poales › Poaceae › PACCAD clade › Panicoideae › Andropogoneae › Saccharum

Protein attributes

Sequence length	215 AA.
Sequence status	Complete.
Protein existence	Inferred from homology.

General annotation (Comments)

Function	Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions By similarity. HAMAP MF_00633
Cofactor	Binds 2 heme groups. One heme group is bound covalently by a single cysteine link, the other one non-covalently By similarity. HAMAP MF_00633
Subunit structure	The 4 large subunits of the cytochrome b6-f complex are cytochrome b6, subunit IV (17 kDa polypeptide, petD), cytochrome f and the Rieske protein, while the 4 small subunits are petG, petL, petM and petN. The complex functions as a dimer By similarity. HAMAP MF_00633
Subcellular location	Plastid › chloroplast thylakoid membrane; Multi-pass membrane protein By similarity HAMAP MF_00633.
Miscellaneous	Heme 1 (or BH or b566) is high-potential and absorbs at about 566 nm, and heme 2 (or BL or b562) is low-potential and absorbs at about 562 nm By similarity. HAMAP MF_00633
Sequence similarities	Belongs to the cytochrome b family. PetB subfamily.

Ontologies

Keywords
Biological process	Electron transport Photosynthesis Transport
Cellular component	Chloroplast Membrane Plastid Thylakoid
Coding sequence diversity	Alternative splicing
Domain	Transmembrane
Ligand	Heme Iron Metal-binding
Gene Ontology (GO)
Biological process	photosynthesis Inferred from electronic annotation. Source: HAMAP respiratory electron transport chain Inferred from electronic annotation. Source: InterPro transport Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	chloroplast Inferred from electronic annotation. Source: UniProtKB-KW integral to membrane Inferred from electronic annotation. Source: UniProtKB-SubCell thylakoid Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity Inferred from electronic annotation. Source: HAMAP iron ion binding Inferred from electronic annotation. Source: UniProtKB-KW oxidoreductase activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: Q6L372-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Note: Inferred from barley, maize and rice transcripts.

Isoform 2 (identifier: Q6L372-2)

The sequence of this isoform differs from the canonical sequence as follows:
     1-2: MS → MSMKFSYTVLGGGVGLVTYLN

Note: Unspliced sequence.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 215	215	Cytochrome b6 HAMAP MF_00633		PRO_0000297694
Regions
	Transmembrane	32 – 52	21	Potential
	Transmembrane	90 – 110	21	Potential
	Transmembrane	116 – 136	21	Potential
	Transmembrane	186 – 206	21	Potential
Sites
	Metal binding	86	1	Iron (heme 2 axial ligand) By similarity
	Metal binding	100	1	Iron (heme 1 axial ligand) By similarity
	Metal binding	187	1	Iron (heme 2 axial ligand) By similarity
	Metal binding	202	1	Iron (heme 1 axial ligand) By similarity
	Binding site	35	1	Heme 1 (covalent; via 1 link) By similarity
Natural variations
	Alternative sequence	1 – 2	2	MS → MSMKFSYTVLGGGVGLVTYL N in isoform 2.		VSP_027360

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified August 21, 2007. Version 2. Checksum: C2E389E17DB51F6A	FASTA	215	24,181
	10 20 30 40 50 60 MSKVYDWFEE RLEIQAIADD ITSKYVPPHV NIFYCLGGIT LTCFLVQVAT GFAMTFYYRP 70 80 90 100 110 120 TVTEAFSSVQ YIMTEANFGW LIRSVHRWSA SMMVLMMILH VFRVYLTGGF KKPRELTWVT 130 140 150 160 170 180 GVVLAVLTAS FGVTGYSLPW DQIGYWAVKI VTGVPEAIPV IGSPLVELLR GSASVGQSTL 190 200 210 TRFYSLHTFV LPLLTAVFML MHFPMIRKQG ISGPL
	Isoform 2. Checksum: A73D093878236F94	FASTA	234	26,182
	10 20 30 40 50 60 MSMKFSYTVL GGGVGLVTYL NKVYDWFEER LEIQAIADDI TSKYVPPHVN IFYCLGGITL 70 80 90 100 110 120 TCFLVQVATG FAMTFYYRPT VTEAFSSVQY IMTEANFGWL IRSVHRWSAS MMVLMMILHV 130 140 150 160 170 180 FRVYLTGGFK KPRELTWVTG VVLAVLTASF GVTGYSLPWD QIGYWAVKIV TGVPEAIPVI 190 200 210 220 230 GSPLVELLRG SASVGQSTLT RFYSLHTFVL PLLTAVFMLM HFPMIRKQGI SGPL

References

[1]

"Structural features and transcript-editing analysis of sugarcane (Saccharum officinarum L.) chloroplast genome." Calsa T. Jr., Carraro D.M., Benatti M.R., Barbosa A.C., Kitajima J.P., Carrer H. Curr. Genet. 46:366-373(2004) [PubMed: 15526204] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. SP-80-3280.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AE009947 Genomic DNA. Translation: AAT44721.1. Sequence problems.
RefSeq	YP_024406.1.
3D structure databases
HSSP	HSSP built from PDB template 1Q90 based on UniProtKB Q00471.
SMR	Q6L372. Positions 4-215.
ModBase	Search...
Genome annotation databases
GeneID	2843846.
Organism-specific databases
Gramene	Q6L372.
Family and domain databases
HAMAP	MF_00633. Cytb6_f_cytb6. [Tree]
InterPro	IPR016175. Cyt_b/b6. 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	PF00033. Cytochrom_B_N. 1 hit. [Graphical view]
PROSITE	PS51002. CYTB_NTER. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CYB6_SACHY

Accession

Primary (citable) accession number: Q6L372

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 21, 2007
Last sequence update:	August 21, 2007
Last modified:	January 19, 2010
This is version 45 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

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