4p00
From Proteopedia
Bacterial Cellulose Synthase in complex with cyclic-di-GMP and UDP
Structural highlights
FunctionQ3J125_CERS4 Catalytic subunit of cellulose synthase. It polymerizes uridine 5'-diphosphate glucose to cellulose.[RuleBase:RU365020] Publication Abstract from PubMedThe bacterial signaling molecule cyclic di-GMP (c-di-GMP) stimulates the synthesis of bacterial cellulose, which is frequently found in biofilms. Bacterial cellulose is synthesized and translocated across the inner membrane by a complex of cellulose synthase BcsA and BcsB subunits. Here we present crystal structures of the c-di-GMP-activated BcsA-BcsB complex. The structures reveal that c-di-GMP releases an autoinhibited state of the enzyme by breaking a salt bridge that otherwise tethers a conserved gating loop that controls access to and substrate coordination at the active site. Disrupting the salt bridge by mutagenesis generates a constitutively active cellulose synthase. Additionally, the c-di-GMP-activated BcsA-BcsB complex contains a nascent cellulose polymer whose terminal glucose unit rests at a new location above BcsA's active site and is positioned for catalysis. Our mechanistic insights indicate how c-di-GMP allosterically modulates enzymatic functions. Mechanism of activation of bacterial cellulose synthase by cyclic di-GMP.,Morgan JL, McNamara JT, Zimmer J Nat Struct Mol Biol. 2014 Apr 6. doi: 10.1038/nsmb.2803. PMID:24704788[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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