title: Structural biochemistry of a Vibrio cholerae dinucleotide cyclase reveals cyclase activity regulation by folates.
abstract: Cyclic dinucleotides are a newly expanded class of second messengers that contribute to the regulation of multiple different pathways in bacterial, eukaryotic, and archaeal cells. The recently identified Vibrio cholerae dinucleotide cyclase (DncV, the gene product of VC0179) can generate three different cyclic dinucleotides and preferentially synthesize a hybrid cyclic-GMP-AMP. Here, we report the crystal structural and functional studies of DncV. We unexpectedly observed a 5-methyltetrahydrofolate diglutamate (5MTHFGLU2) molecule bound in a surface pocket opposite the nucleotide substrate-binding groove of DncV. Subsequent mutagenesis and functional studies showed that the enzymatic activity of DncV is regulated by folate-like molecules, suggesting the existence of a signaling pathway that links folate-like metabolism cofactors to the regulation of cyclic dinucleotide second messenger synthesis. Sequence analysis showed that the residues involved in 5MTHFGLU2 binding are highly conserved in DncV orthologs, implying the presence of this regulation mechanism in a wide variety of bacteria.
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, China.
authors.forename: Deyu
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Centre for Infectious Diseases Research, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Center for Structural Biology, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, China.
authors.forename: Guijun
authors.initials: G
authors.lastname: Shang
authors.affiliation: Centre for Infectious Diseases Research, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, China.
authors.forename: Defen
authors.initials: D
authors.lastname: Lu
authors.affiliation: Centre for Infectious Diseases Research, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Center for Structural Biology, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China; State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Beijing 102206, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
authors.affiliation: Centre for Infectious Diseases Research, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.
authors.forename: Jing-Ren
authors.initials: JR
authors.lastname: Zhang
authors.affiliation: Centre for Infectious Diseases Research, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Center for Structural Biology, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China. Electronic address: yxiang@mail.tsinghua.edu.cn.
authors.forename: Ye
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D020134:Catalytic Domain; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D005492:Folic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D014734:Vibrio cholerae / Q000737:chemistry / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; C020410:5-methyltetrahydrohomofolic acid; D005492:Folic Acid; D000242:Cyclic AMP; D006152:Cyclic GMP