title: Structural characterization of MepB from Staphylococcus aureus reveals homology to endonucleases.
abstract: The MepRAB operon in Staphylococcus aureus has been identified to play a role in drug resistance. Although the functions of MepA and MepR are known, little information is available on the function of MepB. Here we report the X-ray structure of MepB to 2.1 Å revealing its structural similarity to the PD-(D/E)XK family of endonucleases. We further show that MepB binds DNA and RNA, with a higher affinity towards RNA and single stranded DNA than towards double stranded DNA. Notably, the PD-(D/E)XK catalytic active site residues are not conserved in MepB. MepB's association with a drug resistance operon suggests that it plays a role in responding to antimicrobials. This role is likely carried out through MepB's interactions with nucleic acids.
authors: Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Sayeh
authors: S
authors: Agah
authors: Sandra
authors: S
authors: Poulos
authors: Christian
authors: C
authors: Banchs
authors: Salem
authors: S
authors: Faham
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D004720:Endonucleases / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D016415:Sequence Alignment; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D012313:RNA; D004247:DNA; D004720:Endonucleases
keywords: DNA damage; PD-(D/E)XK endonucleases; antimicrobials; drug resistance