User:Tilman Schirmer/Sandbox 211
PleD
OverviewOverview
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from Caulobacter crescentus is a response regulator with an unorthodox catalytic, diguanylate cyclase, output domain. It is composed of a canonical CheY-like response regulator receiver (, also called D1) domain,
a Rec-like (, also called D2) adaptor domain,
and a C-terminal domain that confers the catalytic acitvity.
The GGDEF domain is named after the highly conserved (in PleD it is GGEEF) that locates to a β-hairpin.
Substrate bindingSubstrate binding
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The motif is part of the as identified in the structure of PleD in complex with . The GGDEF domain binds only one GTP substrate molecule. For the reaction to proceed, two GTP loaded GGDEF domains have to align antiparallely.
Complete active siteComplete active site
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After binding of the (here we show GMP, please update), it is believed that two GGDEF domains associate antiparallely to form a catalytically competent dimer (, ). Then, by inter-molecular nucleophilic in-line attack of the O3' atom onto the α-phosphorous of the other GTP substrate molecule, two phosphodiester bonds are formed under release of two pyrophosphate molecules (2 GTP -> c-di-GMP + 2 PPi).
ReferencesReferences
Non-activated PleD structure 1w25: [xtra 1]
Activated PleD structure 2v0n: [xtra 1]
- ↑ Wassmann P, Chan C, Paul R, Beck A, Heerklotz H, Jenal U, Schirmer T. Structure of BeF3- -modified response regulator PleD: implications for diguanylate cyclase activation, catalysis, and feedback inhibition. Structure. 2007 Aug;15(8):915-27. PMID:17697997 doi:http://dx.doi.org/10.1016/j.str.2007.06.016