The role of the tyrosine kinase Wzc (Sll0923) and the phosphatase Wzb (Slr0328) in the production of extracellular polymeric substances (EPS) by Synechocystis PCC 6803

MicrobiologyOpen

Roberto De Philippis¹  Federico Rossi¹  Zsófia Büttel²  Sara B. Pereira³  Paula Tamagnini³  Marina Santos³  Carina Eisfeld³  Luís Gales³  João H. Morais‐Cabral³  Carlos Flores³  José P. Leite³  Rita Mota³ 

[1] Department of Agrifood Production and Environmental Sciences University of Florence Florence Italy;IBMC ‐ Instituto de Biologia Molecular e Celular Universidade do Porto Porto Portugal;i3S ‐ Instituto de Investigação e Inovação em Saúde Universidade do Porto Porto Portugal;

关键词: cyanobacteria;    extracellular polymeric substances;    Synechocystis;    Wzb;    Wzc;   

DOI  :  10.1002/mbo3.753

来源: DOAJ

【 摘 要 】

Abstract Many cyanobacteria produce extracellular polymeric substances (EPS) mainly composed of heteropolysaccharides with unique characteristics that make them suitable for biotechnological applications. However, manipulation/optimization of EPS biosynthesis/characteristics is hindered by a poor understanding of the production pathways and the differences between bacterial species. In this work, genes putatively related to different pathways of cyanobacterial EPS polymerization, assembly, and export were targeted for deletion or truncation in the unicellular Synechocystis sp. PCC 6803. No evident phenotypic changes were observed for some mutants in genes occurring in multiple copies in Synechocystis genome, namely ∆wzy (∆sll0737), ∆wzx (∆sll5049), ∆kpsM (∆slr2107), and ∆kpsM∆wzy (∆slr2107∆sll0737), strongly suggesting functional redundancy. In contrast, Δwzc (Δsll0923) and Δwzb (Δslr0328) influenced both the amount and composition of the EPS, establishing that Wzc participates in the production of capsular (CPS) and released (RPS) polysaccharides, and Wzb affects RPS production. The structure of Wzb was solved (2.28 Å), revealing structural differences relative to other phosphatases involved in EPS production and suggesting a different substrate recognition mechanism. In addition, Wzc showed the ATPase and autokinase activities typical of bacterial tyrosine kinases. Most importantly, Wzb was able to dephosphorylate Wzc in vitro, suggesting that tyrosine phosphorylation/dephosphorylation plays a role in cyanobacterial EPS production.

【 授权许可】

Unknown