RRC ID 1687
Author Taoka M, Yamauchi Y, Shinkawa T, Kaji H, Motohashi W, Nakayama H, Takahashi N, Isobe T.
Title Only a small subset of the horizontally transferred chromosomal genes in Escherichia coli are translated into proteins.
Journal Mol Cell Proteomics
Abstract Horizontally transferred genes are believed to play a critical role in the divergence of bacterial strains from a common ancestor, but whether all of these genes express functional proteins in the cell remains unknown. Here, we used an integrated LC-based protein identification technology to analyze the proteome of Escherichia coli strain K12 (JM109) and identified 1,480 expressed proteins, which are equivalent to approximately 35% of the total open reading frames predicted in the genome. This subset contained proteins with cellular abundance of several dozens to hundreds of thousands of copies, and included nearly all types of proteins in terms of chemical characteristics, subcellular distribution, and function. Interestingly, the subset also contained 138 of 164 gene products that are currently known to be essential for bacterial viability (84% coverage). However, the subset contained only a very small population (10%) of protein products from genes mapped within K-loops, which are "hot spots" for the integration of foreign DNAs within the K12 genome. On the other hand, these genes in K-loops appeared to be transcribed to RNAs almost as efficiently as the native genes in the bacterial cell as monitored by DNA microarray analysis, raising the possibility that most of the recently acquired foreign genes are inadequate for the translational machinery for the native genes and do not generate functional proteins within the cell.
Volume 3(8)
Pages 780-7
Published 2004-8-1
DOI 10.1074/mcp.M400030-MCP200
PII S1535-9476(20)33151-0
PMID 15115803
MeSH Bacterial Proteins / genetics* Bacterial Proteins / isolation & purification Chromatography, Liquid Chromosomes, Bacterial / genetics Escherichia coli K12 / genetics* Gene Transfer, Horizontal* Genome, Bacterial* Mass Spectrometry Oligonucleotide Array Sequence Analysis Protein Biosynthesis*
IF 4.87
Times Cited 70
WOS Category BIOCHEMICAL RESEARCH METHODS
Resource
INFORMATION E.coli