The domain within your query sequence starts at position 295 and ends at position 440; the E-value for the PLCXc domain shown below is 6.76e-76.

All catalytic sites are present in this domain. Check the literature (PubMed 98035056 96186808 97477327 ) for details.



Phospholipase C, catalytic domain (part); domain X
SMART accession number:SM00148
Description: Phosphoinositide-specific phospholipases C. These enzymes contain 2 regions (X and Y) which together form a TIM barrel-like structure containing the active site residues. Phospholipase C enzymes (PI-PLC) act as signal transducers that generate two second messengers, inositol-1,4,5-trisphosphate and diacylglycerol. The bacterial enzyme [6] appears to be a homologue of the mammalian PLCs.
Interpro abstract (IPR000909):

Phosphatidylinositol-specific phospholipase C, a eukaryotic intracellular enzyme, plays an important role in signal transduction processes [ (PUBMED:1849017) ]. It catalyzes the hydrolysis of 1-phosphatidyl-D-myo-inositol-3,4,5-triphosphate into the second messenger molecules diacylglycerol and inositol-1,4,5-triphosphate. This catalytic process is tightly regulated by reversible phosphorylation and binding of regulatory proteins [ (PUBMED:1419362) (PUBMED:1319994) (PUBMED:1335185) ]. In mammals, there are at least 6 different isoforms of PI-PLC, they differ in their domain structure, their regulation, and their tissue distribution. Lower eukaryotes also possess multiple isoforms of PI-PLC. All eukaryotic PI-PLCs contain two regions of homology, sometimes referred to as the 'X-box' and 'Y-box'. The order of these two regions is always the same (NH2-X-Y-COOH), but the spacing is variable. In most isoforms, the distance between these two regions is only 50-100 residues but in the gamma isoforms one PH domain, two SH2 domains, and one SH3 domain are inserted between the two PLC-specific domains. The two conserved regions have been shown to be important for the catalytic activity. By profile analysis, we could show that sequences with significant similarity to the X-box domain occur also in prokaryotic and trypanosome PI-specific phospholipases C. Apart from this region, the prokaryotic enzymes show no similarity to their eukaryotic counterparts.

Family alignment:
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There are 11266 PLCXc domains in 11247 proteins in SMART's nrdb database.

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