title: Molecular characterization of the Borrelia burgdorferi in vivo-essential protein PncA.
abstract: The conversion of nicotinamide to nicotinic acid by nicotinamidase enzymes is a critical step in maintaining NAD(+) homeostasis and contributes to numerous important biological processes in diverse organisms. In Borrelia burgdorferi, the nicotinamidase enzyme, PncA, is required for spirochaete survival throughout the infectious cycle. Mammals lack nicotinamidases and therefore PncA may serve as a therapeutic target for Lyme disease. Contrary to the in vivo importance of PncA, the current annotation for the pncA ORF suggests that the encoded protein may be inactive due to the absence of an N-terminal aspartic acid residue that is a conserved member of the catalytic triad of characterized PncA proteins. Herein, we have used genetic and biochemical strategies to determine the N-terminal sequence of B. burgdorferi PncA. Our data demonstrate that the PncA protein is 24 aa longer than the currently annotated sequence and that pncA translation is initiated from the rare, non-canonical initiation codon AUU. These findings are an important first step in understanding the catalytic function of this in vivo-essential protein.
authors.affiliation: Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida (UCF), Orlando, FL 32827, USA.|Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, MT 59840, USA.
authors.forename: Mollie W
authors.initials: MW
authors.lastname: Jewett
authors.affiliation: Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida (UCF), Orlando, FL 32827, USA.
authors.forename: Sunny
authors.initials: S
authors.lastname: Jain
authors.affiliation: Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida (UCF), Orlando, FL 32827, USA.
authors.forename: Angelika K
authors.initials: AK
authors.lastname: Linowski
authors.affiliation: Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, MT 59840, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Sarkar
authors.affiliation: Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, MT 59840, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Rosa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D025065:Borrelia burgdorferi / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D003062:Codon; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008193:Lyme Disease / Q000382:microbiology*; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D009535:Nicotinamidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010442:Peptide Chain Initiation, Translational; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D003062:Codon; D009243:NAD; D009535:Nicotinamidase