title: Crystal structure of the Bacillus-conserved MazG protein, a nucleotide pyrophosphohydrolase.
abstract: BA1544 from Bacillus anthracis was previously annotated as a transcription factor for the gene cluster ba1554 - ba1558, but has not been experimentally characterized. B. anthracis is an obligate pathogen causing fatal inhalational anthrax, and BA1544 is absolutely conserved in Bacillus species, including Bacillus cereus, Bacillus thuringiensis and Bacillus mycoides, with 100% sequence identity. To address the function of BA1544, we performed structural and biochemical studies, which revealed that BA1544 is a MazG protein. Thus, herein, the protein is defined as Bacillus-conserved MazG (BcMazG). Like other MazG structures, BcMazG assembles into a tetrameric architecture. Each monomer adopts a four-α-helix bundle that accommodates a metal ion using four acidic residues, and presents one putative substrate-binding site. Enzymatic characterization demonstrated that BcMazG is a nucleoside triphosphate (NTP) pyrophosphohydrolase and prefers adenosine triphosphate as a substrate among canonical NTPs. Moreover, structural comparison of BcMazG with its homologues revealed a potential regulation mechanism whereby the enzymatic activity of BcMazG is regulated by its C-terminal region.
authors.affiliation: Division of Biological Science and Technology, Yonsei University, Wonju 220-710, Republic of Korea.
authors.forename: Meong Il
authors.initials: MI
authors.lastname: Kim
authors.affiliation: Division of Biological Science and Technology, Yonsei University, Wonju 220-710, Republic of Korea. Electronic address: minsunhong@yonsei.ac.kr.
authors.forename: Minsun
authors.initials: M
authors.lastname: Hong
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D001409:Bacillus cereus / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D006868:Hydrolysis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D021122:Protein Subunits; D011755:Pyrophosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D011994:Recombinant Proteins; D011755:Pyrophosphatases; C021895:nucleoside triphosphate pyrophosphatase
keywords: Bacillus anthracis; Bacillus cereus; Crystal structure; MazG; Nucleoside triphosphate pyrophosphohydrolase