U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

cysM cysteine synthase B [ Escherichia coli str. K-12 substr. MG1655 ]

Gene ID: 946888, updated on 4-Feb-2026
Official Symbol
cysM
Official Full Name
cysteine synthase B
Primary source
ECOCYC:EG10193
Locus tag
b2421
See related
ASAP:ABE-0007982
Gene type
protein coding
RefSeq status
REVIEWED
Organism
Escherichia coli str. K-12 substr. MG1655 (strain: K-12, substrain: MG1655)
Lineage
Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia
Also known as
ECK2416
Summary
Cysteine synthase B is one of two isozymes in Escherichia coli that catalyze the formation of L-cysteine from O-acetyl-L-serine and sulfide . [More information is available at EcoCyc: EG10193].
Try the new Gene page
Try the new Transcripts and proteins table
Sequence:
NC_000913.3 (2538672..2539583, complement)

NC_000913.3Genomic Context describing neighboring genes Neighboring gene DUF5329 domain-containing protein YfeK Neighboring gene PF05406 family protein YfeS Neighboring gene sulfate/thiosulfate ABC transporter ATP binding subunit Neighboring gene sulfate/thiosulfate ABC transporter inner membrane subunit CysW Neighboring gene sulfate/thiosulfate ABC transporter inner membrane subunit CysU Neighboring gene thiosulfate/sulfate ABC transporter periplasmic binding protein CysP

Genomic Sequence:
NC_000913.3

GeneRIFs: Gene References Into Functions

What's a GeneRIF?
Products Interactant Other Gene Complex Source Pubs Description

Gene Ontology Provided by EcoCyc

Function Evidence Code Pubs
enables L-cysteine desulfhydrase activity IMP
Inferred from Mutant Phenotype
more info
PubMed 
enables cysteine synthase activity IBA
Inferred from Biological aspect of Ancestor
more info
 
enables cysteine synthase activity IDA
Inferred from Direct Assay
more info
PubMed 
enables cysteine synthase activity IEA
Inferred from Electronic Annotation
more info
 
enables lyase activity IEA
Inferred from Electronic Annotation
more info
 
enables protein binding IPI
Inferred from Physical Interaction
more info
PubMed 
enables protein homodimerization activity IDA
Inferred from Direct Assay
more info
PubMed 
enables pyridoxal phosphate binding IDA
Inferred from Direct Assay
more info
PubMed 
enables transferase activity IEA
Inferred from Electronic Annotation
more info
 
enables transferase activity, transferring alkyl or aryl (other than methyl) groups IEA
Inferred from Electronic Annotation
more info
 
Component Evidence Code Pubs
is_active_in cytoplasm IBA
Inferred from Biological aspect of Ancestor
more info
 
Preferred Names
cysteine synthase B
NP_416916.1

NEW Try the new Transcript table

Genome Annotation

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference assembly

Genomic

  1. NC_000913.3 Reference assembly

    Range
    2538672..2539583 complement
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. NP_416916.1 cysteine synthase B

    See identical proteins and their annotated locations for NP_416916.1

    Status: REVIEWED

    UniProtKB/TrEMBL
    A0A775ZIX3
    Conserved Domains (1) summary
    PRK11761
    Location:1294
    cysM; cysteine synthase CysM