title: Nucleotide binding by the widespread high-affinity cyclic di-GMP receptor MshEN domain.
abstract: C-di-GMP is a bacterial second messenger regulating various cellular functions. Many bacteria contain c-di-GMP-metabolizing enzymes but lack known c-di-GMP receptors. Recently, two MshE-type ATPases associated with bacterial type II secretion system and type IV pilus formation were shown to specifically bind c-di-GMP. Here we report crystal structure of the MshE N-terminal domain (MshEN1-145) from Vibrio cholerae in complex with c-di-GMP at a 1.37 Å resolution. This structure reveals a unique c-di-GMP-binding mode, featuring a tandem array of two highly conserved binding motifs, each comprising a 24-residue sequence RLGxx(L/V/I)(L/V/I)xxG(L/V/I)(L/V/I)xxxxLxxxLxxQ that binds half of the c-di-GMP molecule, primarily through hydrophobic interactions. Mutating these highly conserved residues markedly reduces c-di-GMP binding and biofilm formation by V. cholerae. This c-di-GMP-binding motif is present in diverse bacterial proteins exhibiting binding affinities ranging from 0.5 μM to as low as 14 nM. The MshEN domain contains the longest nucleotide-binding motif reported to date.
authors: Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China.
authors: Yu-Chuan
authors: YC
authors: Wang
authors: Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China.
authors: Ko-Hsin
authors: KH
authors: Chin
authors: Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China.
authors: Zhi-Le
authors: ZL
authors: Tu
authors: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
authors: Jin
authors: J
authors: He
authors: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California 95064, USA.
authors: Christopher J
authors: CJ
authors: Jones
authors: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California 95064, USA.
authors: David Zamorano
authors: DZ
authors: Sanchez
authors: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California 95064, USA.
authors: Fitnat H
authors: FH
authors: Yildiz
authors: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA.
authors: Michael Y
authors: http://orcid.org/0000-0002-2265-5572
authors: MY
authors: Galperin
authors: Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China.|Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China.
authors: Shan-Ho
authors: SH
authors: Chou
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D020816:Amino Acid Motifs / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D018441:Biofilms; D018360:Crystallography, X-Ray; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D009154:Mutation; D011485:Protein Binding / Q000502:physiology; D000072417:Protein Domains / Q000502:physiology*; D000069178:Type II Secretion Systems / Q000737:chemistry / Q000378:metabolism; D014734:Vibrio cholerae / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D000069178:Type II Secretion Systems; C062025:bis(3',5')-cyclic diguanylic acid; D000251:Adenosine Triphosphatases; D006152:Cyclic GMP