Family

S-ribosylhomocysteinase (LuxS) (IPR003815)

Short name: S-ribosylhomocysteinase

Family relationships

None.

Description

In bacteria, the regulation of gene expression in response to changes in cell density is called quorum sensing. Quorum-sensing bacteria produce, release, and respond to hormone-like molecules (autoinducers) that accumulate in the external environment as the cell population grows. For example, enteric bacteria use quorum sensing to regulate several traits that allow them to establish and maintain infection in their host, including motility, biofilm formation, and virulence-specific genes [PMID: 17133078]. The LuxS/AI-2 system is one of several quorum sensing mechanisms. AI-2 (autoinducer-2) is a signalling molecule that functions in interspecies communication by regulating niche-specific genes with diverse functions in various bacteria, often in response to population density. LuxS (S-ribosylhomocysteinase; EC:4.4.1.21) is an autoinducer-production protein that has a metabolic function as a component of the activated methyl cycle. LuxS converts S-ribosylhomocysteine to homocysteine and 4,5-dihydroxy-2,3-pentanedione (DPD); DPD can then spontaneously cyclise to active AI-2 [PMID: 16923076, PMID: 15287744]. LuxS is a homodimeric iron-dependent metalloenzyme containing two identical tetrahedral metal-binding sites similar to those found in peptidases and amidases [PMID: 15751951].

GO terms

Biological Process

GO:0009372 quorum sensing

Molecular Function

GO:0043768 S-ribosylhomocysteine lyase activity
GO:0005506 iron ion binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
HAMAP
PRINTS
PIRSF
GENE3D
ProDom
Pfam