Reviewed, UniProtKB/Swiss-Prot P32260 (CYSKP_SPIOL)

Names and origin

Protein names

Recommended name:
    Cysteine synthase, chloroplastic/chromoplastic
    EC=2.5.1.47
Alternative name(s):
    O-acetylserine sulfhydrylase
    CSase B
      Short name=CS-B
    O-acetylserine (thiol)-lyase
    OAS-TL B

Gene names

Name:

CYSK

Organism

Spinacia oleracea (Spinach)

Taxonomic identifier

3562 [NCBI]

Taxonomic lineage

Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › Caryophyllales › Amaranthaceae › Spinacia

Protein attributes

Sequence length	383 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)

Catalytic activity	O(3)-acetyl-L-serine + H2S = L-cysteine + acetate.
Cofactor	Pyridoxal phosphate.
Pathway	Amino-acid biosynthesis; L-cysteine biosynthesis; L-cysteine from L-serine: step 2/2.
Subunit structure	Homodimer.
Subcellular location	Plastid › chloroplast stroma. Plastid › chromoplast.
Sequence similarities	Belongs to the cysteine synthase/cystathionine beta-synthase family.
Biophysicochemical properties	Kinetic parameters: KM=1.3 mM for O-acetylserine KM=0.25 mM for sulfide pH dependence: Optimum pH is 7.5 to 8.5.

Ontologies

Keywords
Biological process	Amino-acid biosynthesis Cysteine biosynthesis
Cellular component	Chloroplast Chromoplast Plastid
Domain	Transit peptide
Ligand	Pyridoxal phosphate
Molecular function	Transferase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	cysteine biosynthetic process from serine Inferred from electronic annotation. Source: InterPro
Cellular component	chloroplast stroma Inferred from electronic annotation. Source: UniProtKB-SubCell chromoplast Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	cysteine synthase activity Inferred from electronic annotation. Source: EC pyridoxal phosphate binding Inferred from electronic annotation. Source: InterPro transferase activity Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Transit peptide	1 – 52	52	Chloroplast and chromoplast Ref.5
	Chain	53 – 383	331	Cysteine synthase, chloroplastic/chromoplastic		PRO_0000006352
Regions
	Region	243 – 247	5	Pyridoxal phosphate binding By similarity
Sites
	Binding site	139	1	Pyridoxal phosphate By similarity
	Binding site	331	1	Pyridoxal phosphate By similarity
Amino acid modifications
	Modified residue	108	1	N6-(pyridoxal phosphate)lysine
Experimental info
	Sequence conflict	12	1	L → I in BAA03542. Ref.1
	Sequence conflict	58	1	Missing AA sequence Ref.5
	Sequence conflict	166	1	E → EKESYLE Ref.3
	Sequence conflict	252 – 258	7	GRYLKER → DGTSKNA in AAA16973. Ref.3
	Sequence conflict	274 – 280	7	ILSGGKP → YFLVESA in AAA16973. Ref.3
	Sequence conflict	334 – 335	2	AA → RG in AAA16973. Ref.3
	Sequence conflict	334 – 335	2	AA → RR in CAA47329. Ref.2
	Sequence conflict	379 – 380	2	NM → KL in AAA16973. Ref.3
	Sequence conflict	383	1	E → EI in AAA16973. Ref.3

Sequences

	Sequence		Length	Mass (Da)
	P32260-1 [UniParc]. Last modified December 1, 2000. Version 2. Checksum: CE3725796D3A3F93	FASTA	383	40,637
	10 20 30 40 50 60 MASLVNNAYA ALRTSKLELR EVKNLANFRV GPPSSLSCNN FKKVSSSPIT CKAVSLSPPS 70 80 90 100 110 120 TIEGLNIAED VSQLIGKTPM VYLNNVSKGS VANIAAKLES MEPCCSVKDR IGYSMIDDAE 130 140 150 160 170 180 QKGVITPGKT TLVEPTSGNT GIGLAFIAAA RGYKITLTMP ASMSMERRVI LKAFGAELVL 190 200 210 220 230 240 TDPAKGMKGA VEKAEEILKK TPDSYMLQQF DNPANPKIHY ETTGPEIWED TKGKVDIFVA 250 260 270 280 290 300 GIGTGGTISG VGRYLKERNP GVQVIGIEPT ESNILSGGKP GPHKIQGLGA GFVPSNLDLG 310 320 330 340 350 360 VMDEVIEVSS EEAVEMAKQL AMKEGLLVGI SSGAAAAAAV RIGKRPENAG KLIAVVFPSF 370 380 GERYLSSILF QSIREECENM KPE

References

[1]	"cDNA cloning and expression of cysteine synthase B localized in chloroplasts of Spinacia oleracea." Saito K., Tatsuguchi K., Murakoshi I., Hirano H. FEBS Lett. 324:247-252(1993) [PubMed: 8405359] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"O-acetylserine(thiol)lyase from spinach (Spinacia oleracea L.) leaf: cDNA cloning, characterization, and overexpression in Escherichia coli of the chloroplast isoform." Rolland N., Droux M., Lebrun M., Douce R. Arch. Biochem. Biophys. 300:213-222(1993) [PubMed: 8424655] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Leaf.
[3]	"An O-acetylserine (thiol) lyase cDNA from spinach." Hell R., Schuster G., Gruissem W. Plant Physiol. 102:1057-1058(1993) [PubMed: 8278530] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: cv. Marathon. Tissue: Leaf.
[4]	"Spinach chloroplast O-acetylserine (thiol)-lyase exhibits two catalytically non-equivalent pyridoxal-5'-phosphate-containing active sites." Rolland N., Ruffet M.-L., Job D., Douce R., Droux M. Eur. J. Biochem. 236:272-282(1996) [PubMed: 8617276] [Abstract] Cited for: PARTIAL PROTEIN SEQUENCE, CHARACTERIZATION.
[5]	"Purification and characterization of O-acetylserine (thiol) lyase from spinach chloroplasts." Droux M., Martin J., Sajus P., Douce R. Arch. Biochem. Biophys. 295:379-390(1992) [PubMed: 1375015] [Abstract] Cited for: PROTEIN SEQUENCE OF 53-65, CHARACTERIZATION.
[6]	"Common sequence motifs coding for higher-plant and prokaryotic O-acetylserine (thiol)-lyases: bacterial origin of a chloroplast transit peptide?" Rolland N., Job D., Douce R. Biochem. J. 293:829-833(1993) [PubMed: 7916619] [Abstract] Cited for: DISCUSSION OF SEQUENCE.

Cross-references

Sequence databases
EMBLGenBankDDBJ	D14722 mRNA. Translation: BAA03542.1. X66860 mRNA. Translation: CAA47329.1. L05184 mRNA. Translation: AAA16973.1.
PIR	S29733. T09000.
3D structure databases
HSSP	HSSP built from PDB template 1FCJ based on UniProtKB P12674.
SMR	P32260. Positions 67-383.
ModBase	Search...
Enzyme and pathway databases
BRENDA	2.5.1.47. 286.
Family and domain databases
InterPro	IPR001216. Cys_synth_BS. IPR005856. Cys_synthKM. IPR005859. CysK. IPR001926. PyrdxlP-dep_enz_bsu. [Graphical view]
Pfam	PF00291. PALP. 1 hit. [Graphical view]
TIGRFAMs	TIGR01139. cysK. 1 hit. TIGR01136. cysKM. 1 hit.
PROSITE	PS00901. CYS_SYNTHASE. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CYSKP_SPIOL

Accession

Primary (citable) accession number: P32260
Secondary accession number(s): Q33137

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1993
Last sequence update:	December 1, 2000
Last modified:	June 16, 2009
This is version 69 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)