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Membrane association of SadC enhances its diguanylate cyclase activity to control exopolysaccharides synthesis and biofilm formation in Pseudomonas aeruginosa
Author(s) -
Zhu Bin,
Liu Cuilan,
Liu Shiheng,
Cong Hengjiang,
Chen Yihuan,
Gu Lichuan,
Ma Luyan Z.
Publication year - 2016
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13263
Subject(s) - biofilm , biology , pseudomonas aeruginosa , motility , second messenger system , microbiology and biotechnology , bacteria , signal transduction , genetics
Summary Cyclic diguanosine monophosphate (c‐di‐GMP) is one of the most important bacterial second messengers that controls many bacterial cellular functions including lifestyle switch between plankton and biofilm. Surface attachment defective (SadC) is a diguanylate cyclase (DGC) involved in the biosynthesis of c‐di‐GMP in Pseudomonas aeruginosa , an opportunistic pathogen that can cause diverse infections. Here we report the crystal structure of GGDEF domain from SadC and the critical role of the trans‐membrane (TM) domain of SadC with regard to biofilm formation, exopolysaccharide production and motility. We showed that over‐expression of SadC in P. aeruginosa PAO1 totally inhibited swimming motility and significantly enhanced the production of exopolysaccharide Psl. SadC lacking TM domains (SadC 300–487 ) could not localize on cytoplasmic membrane and form cluster, lost the ability to inhibit the swimming and twitching motility, and showed the attenuated activity to promote Psl production despite that SadC 300–487 was able to catalyze the synthesize of c‐di‐GMP in vitro and in vivo . The GGDEF domain of SadC has a typical GGDEF structure and the α‐helix connected the TM domains with SadC GGDEF domain is essential for SadC to form DGC oligomers. Our data imply that membrane association of SadC promotes its DGC activity by affecting the formation of active DGC oligomers.