title: Identification of commonly expressed exoproteins and proteolytic cleavage events by proteomic mining of clinically relevant UK isolates ofStaphylococcus aureus.
abstract: The range of exoproteins and core exoproteome of 14Staphylococcus aureusisolates representing major lineages associated with asymptomatic carriage and clinical disease in the UK was identified by MS proteomics using a combined database incorporating sequences derived from 39S. aureusgenomes. In all, 632 different proteins were identified and, of these, only 52 (8 %) were found in all 14 isolates whereas 144 (23 %) were found in just a single isolate. Comparison of the observed mass of each protein (based on migration by SDS-PAGE) with its predicted mass (based on amino acid sequence) suggested that 95 % of the proteins identified were not subject to any major post-translational modification. Migration of 5 % of the proteins was not as expected: 1 % of the proteins migrated at a mass greater than predicted, while 4 % appeared to have undergone proteolytic cleavage; these included SsaA2, Aur, SspP, Ebh as well as BlaR1, MecR1, FsH, OatA and LtaS. Intriguingly, a truncated SasG was produced by a single CC8 USA300-like strain. The analysis provided evidence of the marked heterogeneity in protein expression byS. aureusin broth, while yielding a core but narrow common exoproteome.
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Debra S
authors.initials: DS
authors.lastname: Smith
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Siggins
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Gierula
authors.affiliation: 2​Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, National Infection Service, Public Health England, 61 Colindale Avenue, London, NW9 5EQ, United Kingdom.
authors.forename: Bruno
authors.initials: B
authors.lastname: Pichon
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Turner
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Nicola N
authors.initials: NN
authors.lastname: Lynskey
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Mia
authors.initials: M
authors.lastname: Mosavie
authors.affiliation: 2​Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, National Infection Service, Public Health England, 61 Colindale Avenue, London, NW9 5EQ, United Kingdom.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Kearns
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Edwards
authors.affiliation: 1​Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom.
authors.forename: Shiranee
authors.initials: S
authors.lastname: Sriskandan
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics; D020543:Proteome; D040901:Proteomics; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000235:genetics* / Q000378:metabolism*; D006113:United Kingdom; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D020543:Proteome; D037521:Virulence Factors
keywords: MS; SasG; Staphylococcus aureus; proteolysis