RelA/SpoT family (IPR004811)

Short name: RelA/Spo_fam

Overlapping homologous superfamilies


Family relationships



The functions of Escherichia coli RelA and SpoT differ somewhat. RelA (EC: produces pppGpp (or ppGpp) from ATP and GTP (or GDP). SpoT is a bifunctional enzyme; it degrades ppGpp, but can also act as a ppGpp synthetase. The two proteins are strongly similar. In many species, a single homologue to SpoT and RelA appears responsible for both ppGpp synthesis and ppGpp degradation [PMID: 9383190, PMID: 11545276].

(p)ppGpp (alarmone) is a regulatory metabolite of the stringent response, which is characterised by growth arrest and the modulation of gene expression in response to various nutritional stresses [PMID: 15866041].

GO terms

Biological Process

GO:0015969 guanosine tetraphosphate metabolic process

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.