User:Tilman Schirmer/Sandbox 200
Cyclic di-GMP signaling
IntroIntro
The cyclic dinucleotide c-di-GMP is a second messenger that mediates the regulation of cell sur-
face associated traits in bacteria. The regulatory network includes
- GGDEF and EAL domain proteins that catalyze c-di-GMP synthesis and degradation, respectively (and thereby control the cellular c-di-GMP level)
and
- PlzD domains as part of down-stream c-di-GMP receptors.
Diguanylate cyclasesDiguanylate cyclases
The condensation reaction 2 GTP -> c-di-GMP + 2 PPi is catalyzed by GGDEF domains that typically occur in combination with sensory or regulator domains. The structures of two diguanylate cyclases (PleD and WspR) have been determined, both being response regulators with a response regulator receiver (Rec) and a GGDEF output (effector) domain. Response regulators are activated through phosphorylation of a conserved aspartate by cognate histidine kinases.
PleDPleD
PleD catalysis PleD catalysis
PleD activation PleD activation
PleD allosteric product inhibition PleD allosteric product inhibition
WspRWspR
C-di-GMP specific phosphodiesterasesC-di-GMP specific phosphodiesterases
Cleavage of one of the phosphodiester bonds is catalyzed by EAL and HD-GYP domains. Thereby, the cylic dinucleotide c-di-GMP is converted to the linear pGpG form.
Two structures of EAL domain proteins have been determined in complex with substrate c-di-GMP (YkuI 2w27 and BlrP1 3gg0) and are presented here.
C-di-GMP receptors with PilZ domainC-di-GMP receptors with PilZ domain
ReferencesReferences
Reviews:
- Schirmer. T. and Jenal. U. (2009), in press.
- ↑ Hengge R. Principles of c-di-GMP signalling in bacteria. Nat Rev Microbiol. 2009 Apr;7(4):263-73. PMID:19287449 doi:10.1038/nrmicro2109
- ↑ Jenal U, Malone J. Mechanisms of cyclic-di-GMP signaling in bacteria. Annu Rev Genet. 2006;40:385-407. PMID:16895465 doi:10.1146/annurev.genet.40.110405.090423