Identification of a chloroform-soluble membrane miniprotein in Escherichia coli and its homolog in Salmonella typhimurium.
Two homologous 29 amino acid-long highly hydrophobic membrane miniproteins were identified in the Bligh-Dyer lipid extracts of Escherichia coli and Salmonella typhimurium using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The amino acid sequences of the proteins were determined by collision-induced dissociation tandem mass spectrometry, in conjunction with a translating BLAST (tBLASTn) search, i.e., comparing the MS/MS-determined protein query sequence against the six-frame translations of the nucleotide sequences of the E. coli and S. typhimurium genomes. Further MS characterization revealed that both proteins retain the N-terminal initiating formyl-methionines. The methodologies described here may be amendable for detecting and characterizing small hydrophobic proteins in other organisms that are difficult to annotate or analyze by conventional methods.
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA. ziqiang.guan@duke.edu
Ziqiang
Z
Guan
Xiaoyuan
X
Wang
Christian R H
CR
Raetz
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D002725:Chloroform / Q000737:chemistry; D002853:Chromatography, Liquid; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D016680:Genome, Bacterial; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D012486:Salmonella typhimurium / Q000737:chemistry* / Q000235:genetics; D021241:Spectrometry, Mass, Electrospray Ionization
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C558798:YnhF protein, E coli; D002725:Chloroform