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High level, context dependent misincorporation of lysine for arginine in Saccharomyces cerevisiae al homeodomain expressed in Escherichia coli
Author(s) -
Forman Michael D.,
Stack Robert F.,
Masters Paul S.,
Hauer Charles R.,
Baxter Susan M.
Publication year - 1998
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.5560070231
Subject(s) - escherichia coli , lysine , saccharomyces cerevisiae , arginine , transfer rna , biology , biochemistry , gene , context (archaeology) , microbiology and biotechnology , recombinant dna , amino acid , chemistry , rna , paleontology
The Saccharomyces cerevisiae al homeodomain is expressed as a soluble protein in Escherichia coli when cultured in minimal medium. Nuclear magnetic resonance (NMR) spectra of previously prepared al homeodomain samples contained a subset of doubled and broadened resonances. Mass spectroscopic and NMR analysis demonstrates that the heterogeneity is largely due to a lysine misincorporation at the arginine (Arg) 115 site. Arg 115 is coded by the 5′‐AGA‐3′ sequence, which is quite rare in E. coli genes. Lower level mistranslation at three other rare arginine codons also occurs. The percentage of lysine for arginine misincorporation in al homeodomain production is dependent on media composition. The dnaY gene, which encodes the rare 5′‐AGA‐3′ tRNA ARG , was co‐expressed in E. coli with the al‐encoding plasmid to produce a homogeneous recombinant al homeodomain. Co‐expression of the dnaY gene completely blocks mistranslation of arginine to lysine during al overexpression in minimal media, and homogeneous protein is produced.