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Title: Staphylococcal SCCmec elements encode an active MCM-like helicase and thus may be replicative

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a public-health threat worldwide. Although the mobile genomic island responsible for this phenotype, staphylococcal cassette chromosome (SCC), has been thought to be nonreplicative, we predicted DNA-replication-related functions for some of the conserved proteins encoded by SCC. We show that one of these, Cch, is homologous to the self-loading initiator helicases of an unrelated family of genomic islands, that it is an active 3'-to-5' helicase and that the adjacent ORF encodes a single-stranded DNA–binding protein. Our 2.9-Å crystal structure of intact Cch shows that it forms a hexameric ring. Cch, like the archaeal and eukaryotic MCM-family replicative helicases, belongs to the pre–sensor II insert clade of AAA+ ATPases. Additionally, we found that SCC elements are part of a broader family of mobile elements, all of which encode a replication initiator upstream of their recombinases. Replication after excision would enhance the efficiency of horizontal gene transfer.

Authors:
 [1];  [1];  [2];  [1];  [3];  [1]
  1. Univ. of Chicago, IL (United States). Dept. of Biochemistry and Molecular Biology
  2. Univ. of Chicago, IL (United States). Dept. of Biochemistry and Molecular Biology; Abbott Lab., North Chicago, IL (United States)
  3. Univ. of Chicago, IL (United States). Dept. of Pediatrics; Univ. of Chicago, IL (United States). MRSA Research Center
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE Office of Science (SC); National Institutes of Health (NIH)
OSTI Identifier:
1347024
DOE Contract Number:
R21AI117593
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nature Structural & Molecular Biology; Journal Volume: 23; Journal Issue: 10
Country of Publication:
United States
Language:
ENGLISH
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Mir-Sanchis, Ignacio, Roman, Christina A., Misiura, Agnieszka, Pigli, Ying Z., Boyle-Vavra, Susan, and Rice, Phoebe A. Staphylococcal SCCmec elements encode an active MCM-like helicase and thus may be replicative. United States: N. p., 2016. Web. doi:10.1038/nsmb.3286.
Mir-Sanchis, Ignacio, Roman, Christina A., Misiura, Agnieszka, Pigli, Ying Z., Boyle-Vavra, Susan, & Rice, Phoebe A. Staphylococcal SCCmec elements encode an active MCM-like helicase and thus may be replicative. United States. doi:10.1038/nsmb.3286.
Mir-Sanchis, Ignacio, Roman, Christina A., Misiura, Agnieszka, Pigli, Ying Z., Boyle-Vavra, Susan, and Rice, Phoebe A. 2016. "Staphylococcal SCCmec elements encode an active MCM-like helicase and thus may be replicative". United States. doi:10.1038/nsmb.3286.
@article{osti_1347024,
title = {Staphylococcal SCCmec elements encode an active MCM-like helicase and thus may be replicative},
author = {Mir-Sanchis, Ignacio and Roman, Christina A. and Misiura, Agnieszka and Pigli, Ying Z. and Boyle-Vavra, Susan and Rice, Phoebe A.},
abstractNote = {Methicillin-resistant Staphylococcus aureus (MRSA) is a public-health threat worldwide. Although the mobile genomic island responsible for this phenotype, staphylococcal cassette chromosome (SCC), has been thought to be nonreplicative, we predicted DNA-replication-related functions for some of the conserved proteins encoded by SCC. We show that one of these, Cch, is homologous to the self-loading initiator helicases of an unrelated family of genomic islands, that it is an active 3'-to-5' helicase and that the adjacent ORF encodes a single-stranded DNA–binding protein. Our 2.9-Å crystal structure of intact Cch shows that it forms a hexameric ring. Cch, like the archaeal and eukaryotic MCM-family replicative helicases, belongs to the pre–sensor II insert clade of AAA+ ATPases. Additionally, we found that SCC elements are part of a broader family of mobile elements, all of which encode a replication initiator upstream of their recombinases. Replication after excision would enhance the efficiency of horizontal gene transfer.},
doi = {10.1038/nsmb.3286},
journal = {Nature Structural & Molecular Biology},
number = 10,
volume = 23,
place = {United States},
year = 2016,
month = 8
}
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