Originally published In Press as doi:10.1074/mcp.M800246-MCP200 on November 28, 2008.
Molecular & Cellular Proteomics 8:735-751, 2009.
© 2009 by The American Society for Biochemistry and Molecular Biology, Inc.
Research
Novel Multiprotein Complexes Identified in the Hyperthermophilic Archaeon Pyrococcus furiosus by Non-denaturing Fractionation of the Native Proteome*,S
Angeli Lal Menon ,
Farris L. Poole, II ,
Aleksandar Cvetkovic ,
Sunia A. Trauger ,
Ewa Kalisiak ,
Joseph W. Scott ,
Saratchandra Shanmukh ,
Jeremy Praissman ,
Francis E. Jenney, Jr. ,¶,
William R. Wikoff ,
John V. Apon ,
Gary Siuzdak and
Michael W. W. Adams ,||
From the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602 and the Scripps Center for Mass Spectrometry and the Departments of Molecular Biology and Chemistry, The Scripps Research Institute, La Jolla, California 92037
Virtually all cellular processes are carried out by dynamic molecular assemblies or multiprotein complexes, the compositions of which are largely undefined. They cannot be predicted solely from bioinformatics analyses nor are there well defined techniques currently available to unequivocally identify protein complexes (PCs). To address this issue, we attempted to directly determine the identity of PCs from native microbial biomass using Pyrococcus furiosus, a hyperthermophilic archaeon that grows optimally at 100 °C, as the model organism. Novel PCs were identified by large scale fractionation of the native proteome using non-denaturing, sequential column chromatography under anaerobic, reducing conditions. A total of 967 distinct P. furiosus proteins were identified by mass spectrometry (nano LC-ESI-MS/MS), representing 80% of the cytoplasmic proteins. Based on the co-fractionation of proteins that are encoded by adjacent genes on the chromosome, 106 potential heteromeric PCs containing 243 proteins were identified, only 20 of which were known or expected. In addition to those of unknown function, novel and uncharacterized PCs were identified that are proposed to be involved in the metabolism of amino acids (10), carbohydrates (four), lipids (two), vitamins and metals (three), and DNA and RNA (nine). A further 30 potential PCs were classified as tentative, and the remaining potential PCs (13) were classified as weakly interacting. Some major advantages of native biomass fractionation for PC identification are that it provides a road map for the (partial) purification of native forms of novel and uncharacterized PCs, and the results can be utilized for the recombinant production of low abundance PCs to provide enough material for detailed structural and biochemical analyses.
|| To whom correspondence should be addressed. E-mail: adams{at}bmb.uga.edu

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Copyright © 2009 by the American Society for Biochemistry and Molecular Biology.
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