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Citrate synthase



Streptomyces hygroscopicus
Reviewed-Annotation score: Annotation score: 3 out of 5-Experimental evidence at protein leveli



Citrate synthase is found in nearly all cells capable of oxidative metabolism.

Catalytic activityi

Acetyl-CoA + H2O + oxaloacetate = citrate + CoA.PROSITE-ProRule annotation

Enzyme regulationi

Allosterically inhibited by NADH.

Pathwayi: tricarboxylic acid cycle

This protein is involved in step 1 of the subpathway that synthesizes isocitrate from oxaloacetate.
Proteins known to be involved in the 2 steps of the subpathway in this organism are:
  1. Citrate synthase (gltA), Citrate synthase (SHXM_04367)
  2. no protein annotated in this organism
This subpathway is part of the pathway tricarboxylic acid cycle, which is itself part of Carbohydrate metabolism.
View all proteins of this organism that are known to be involved in the subpathway that synthesizes isocitrate from oxaloacetate, the pathway tricarboxylic acid cycle and in Carbohydrate metabolism.

GO - Molecular functioni

GO - Biological processi


Molecular functionTransferase
Biological processTricarboxylic acid cycle

Enzyme and pathway databases

UniPathwayiUPA00223; UER00717.

Names & Taxonomyi

Protein namesi
Recommended name:
Citrate synthase (EC:
Gene namesi
OrganismiStreptomyces hygroscopicus
Taxonomic identifieri1912 [NCBI]
Taxonomic lineageiBacteriaActinobacteriaStreptomycetalesStreptomycetaceaeStreptomyces

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001699721 – ›20Citrate synthaseAdd BLAST›20


Subunit structurei


Family & Domainsi

Sequence similaritiesi

Belongs to the citrate synthase family.Curated

Phylogenomic databases

eggNOGiENOG4105BZN. Bacteria.
COG0372. LUCA.


Sequence statusi: Fragment.

P20903-1 [UniParc]FASTAAdd to basket

« Hide

        10         20
Mass (Da):2,234
Last modified:February 1, 1991 - v1

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Non-terminal residuei201

Sequence databases


Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.

Entry informationi

Entry nameiCISY_STRHY
AccessioniPrimary (citable) accession number: P20903
Entry historyiIntegrated into UniProtKB/Swiss-Prot: February 1, 1991
Last sequence update: February 1, 1991
Last modified: July 5, 2017
This is version 57 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program


Keywords - Technical termi

Allosteric enzyme, Direct protein sequencing


  1. PATHWAY comments
    Index of metabolic and biosynthesis pathways
  2. SIMILARITY comments
    Index of protein domains and families