Effect of PlzD, a YcgR homologue of c-di-GMP-binding protein, on polar flagellar motility in Vibrio alginolyticus. (18th February 2019)

• Record Type: Journal Article
• Authors: Kojima, Seiji; Yoneda, Takuro; Morimoto, Wakako; Homma, Michio
• Is Part Of: Journal of biochemistry. Volume 166:Number 1(2019)
• Page Start: 77
• Page End: 88
• Publication Date: 2019-02-18
• Subjects: c-di-GMP -- flagellar motor -- motility inhibition -- polar flagellum -- YcgR; Biochemistry -- Periodicals; Biochemistry -- Periodicals; Electronic journals; 572.05
• DOI: 10.1093/jb/mvz014
• Languages: English
• ISSNs: 0021-924X

Abstract

Abstract: YcgR, a cyclic diguanylate (c-di-GMP)-binding protein expressed in Escherichia coli, brakes flagellar rotation by binding to the motor in a c-di-GMP dependent manner and has been implicated in triggering biofilm formation. Vibrio alginolyticus has a single polar flagellum and encodes YcgR homologue, PlzD. When PlzD or PlzD-GFP was highly over-produced in nutrient-poor condition, the polar flagellar motility of V. alginolyticus was reduced. This inhibitory effect is c-di-GMP independent as mutants substituting putative c-di-GMP-binding residues retain the effect. Moderate over-expression of PlzD-GFP allowed its localization at the flagellated cell pole. Truncation of the N-terminal 12 or 35 residues of PlzD abolished the inhibitory effect and polar localization, and no inhibitory effect was observed by deleting plzD or expressing an endogenous level of PlzD-GFP. Subcellular fractionation showed that PlzD, but not its N-terminally truncated variants, was precipitated when over-produced. Moreover, immunoblotting and N-terminal sequencing revealed that endogenous PlzD is synthesized from Met33. These results suggest that an N-terminal extension allows PlzD to localize at the cell pole but causes aggregation and leads to inhibition of motility. In V. alginolyticus, PlzD has a potential property to associate with the polar flagellar motor but this interaction is too weak to inhibit rotation.