4i86 | pdb_00004i86
Crystal structure of PilZ domain of CeSA from cellulose synthesizing bacterium
Structural highlights
FunctionACSA1_KOMXY Bifunctional protein comprised of a catalytic subunit and a regulatory subunit. The catalytic subunit of cellulose synthase polymerizes uridine 5'-diphosphate glucose to cellulose in a processive way. The thick cellulosic mats generated by this enzyme probably provide a specialized protective environment to the bacterium. The regulatory subunit binds bis-(3'-5') cyclic diguanylic acid (c-di-GMP).[1] Publication Abstract from PubMedIn some Proteobacteria and Firmicutes such as Pseudomonas aeruginosa, Vibrio cholerae, Xanthomonas campestris, and Clostridium difficile, cyclic dimeric guanosine monophosphate (c-di-GMP) is known to regulate cellular processes, including motility, biofilm formation, and virulence, as a second messenger. Cellulose production in Acetobacter xylinum, a model organism of cellulose biosynthesis, also depends on by cellular c-di-GMP level. In cellulose-synthesizing bacteria, a terminal complex localized in the cell membrane synthesizes cellulose and regulates the production of cellulose sensed by c-di-GMP. Although previous studies indicated that the PilZ domain conserved in cellulose synthase subunit A (CeSA) was part of a receptor for c-di-GMP, the recognition mechanism by PilZ domain of CeSA remains unclear. In the present study, we studied the interaction between c-di-GMP and the PilZ domain of CeSA from a structural viewpoint. First, we solved the crystal structure of the PilZ domain of CeSA from A. xylinum (AxCeSA-PilZ) at 2.1A resolution. Then, comparison of the sequence and structure of AxCeSA-PilZ to those of known structures of PilZ, such as VCA0042, PP4397, and PA4608, indicated the involvement of Lys573 and Arg643 of AxCeSA-PilZ in the recognition of c-di-GMP besides the RxxxR motif. Finally, the binding characteristics of c-di-GMP to AxCeSA-PilZ and mutants were determined with isothermal titration calorimetry, indicating that the residues corresponding to Lys573 and Arg643 in AxCeSA-PilZ generally contribute to the binding of c-di-GMP to PilZ. The c-di-GMP recognition mechanism of the PilZ domain of bacterial cellulose synthase subunit A.,Fujiwara T, Komoda K, Sakurai N, Tajima K, Tanaka I, Yao M Biochem Biophys Res Commun. 2013 Feb 22;431(4):802-7. doi:, 10.1016/j.bbrc.2012.12.103. Epub 2013 Jan 4. PMID:23291177[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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