Comparative Proteomics Enables Identification of Nonannotated Cold Shock Proteins in E. coli.

ABSTRACT: Recent advances in mass spectrometry-based proteomics have revealed translation of previously nonannotated microproteins from thousands of small open reading frames (smORFs) in prokaryotic and eukaryotic genomes. Facile methods to determine cellular functions of these newly discovered microproteins are now needed. Here, we couple semiquantitative comparative proteomics with whole-genome database searching to identify two nonannotated, homologous cold shock-regulated microproteins in Escherichia coli K12 substr. MG1655, as well as two additional constitutively expressed microproteins. We apply molecular genetic approaches to confirm expression of these cold shock proteins (YmcF and YnfQ) at reduced temperatures and identify the noncanonical ATT start codons that initiate their translation.

SUBMITTER: D'Lima NG 

PROVIDER: S-EPMC5647875 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature