Top-Down Proteomics Reveals Novel Protein Forms Expressed in Methanosarcina acetivorans

Jonathan T. Ferguson, Craig D. Wenger, William W. Metcalf, Neil L. Kelleher*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


Using both automated nanospray and online liquid chromatography mass spectrometry LC-MS strategies, 99 proteins have been newly identified by top-down tandem mass spectrometry (MS/MS) in Methanosarcina acetivorans, the methanogen with the largest known genome [5.7 mega base pairs (Mb)] for an Archaeon. Because top-down MS/MS was used, 15 proteins were detected with mispredicted start sites along with an additional five from small open reading frames (SORFs). Beyond characterization of these more common discrepancies in genome annotation, one SORF resulted from a rare start codon (AUA) as the initiation site for translation of this protein. Also, a methylation on a 30S ribosomal protein (MA1259) was localized to Pro59-Val69, contrasting sharply from its homologue in Escherichia coli (rp S12) known to harbor an unusual β-thiomethylated aspartic acid residue.

Original languageEnglish (US)
Pages (from-to)1743-1750
Number of pages8
JournalJournal of the American Society for Mass Spectrometry
Issue number9
StatePublished - Sep 2009

ASJC Scopus subject areas

  • Structural Biology
  • Spectroscopy


Dive into the research topics of 'Top-Down Proteomics Reveals Novel Protein Forms Expressed in Methanosarcina acetivorans'. Together they form a unique fingerprint.

Cite this