Bacillus subtilis 5′-nucleotidases with various functions and substrate specificities. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Terakawa, Ayako; Natsume, Ayane; Okada, Atsushi; Nishihata, Shogo; Kuse, Junko; Tanaka, Kosei; Takenaka, Shinji; Ishikawa, Shu; Yoshida, Ken-ichi
• Is Part Of: BMC microbiology. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 13
• Publication Date: 2016-12
• Subjects: Bacillus subtilis -- Haloacid dehalogenase superfamily -- Inositol monophosphatase -- Inositol phosphate -- Nucleoside/nucleotide metabolism -- 5′-nucleotidase -- Oxidative stress -- Phosphatase -- Protein motif; Microbiology -- Periodicals; 579.05
• DOI: 10.1186/s12866-016-0866-5
• Languages: English
• ISSNs: 1471-2180

Abstract

Abstract Background InEscherichia coli, nagD, yrfG, yjjG, yieH, yigL, surE, andyfbR encode 5′-nucleotidases that hydrolyze the phosphate group of 5′-nucleotides. InBacillus subtilis, genes encoding 5′-nucleotidase have remained to be identified. Results We found thatB. subtilis ycsE, araL, yutF, ysaA, andyqeG show suggestive similarities tonagD . Here, we expressed them inE. coli to purify the respective His6 -tagged proteins. YcsE exhibited significant 5′-nucleotidase activity with a broader specificity, whereas the other four enzymes had rather weak but suggestive activities with various capacities and substrate specificities. In contrast, B. subtilis yktC shares high similarity withE. coli suhB encoding an inositol monophosphatase. YktC exhibited inositol monophosphatase activity as well as 5′-nucleotidase activity preferential for GMP and IMP. TheycsE, yktC, andyqeG genes are induced by oxidative stress and were dispensable, althoughyqeG was required to maintain normal growth on solid medium. In the presence of diamide, only mutants lackingyktC exhibited enhanced growth defects, whereas the other mutants withoutycsE oryqeG did not. Conclusions Accordingly, inB. subtilis, at least YcsE and YktC acted as major 5′-nucleotidases and the four minor enzymes might function when the intracellular concentrations of substrates are sufficiently high. In addition, YktC is involved in resistance to oxidative stress caused by diamide, while YqeG is necessary for normal colony formation on solid medium.