Open AccessProtein Synthesis in Escherichia coli with Mischarged tRNA
Author(s) -
Bokkee Min,
Makoto Kitabatake,
Carla Polycarpo,
Joanne Pelaschier,
Gregory Raczniak,
Benfang Ruan,
Hiroyuki Kobayashi,
Suk Namgoong,
Dieter Söll
Publication year - 2003
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.185.12.3524-3526.2003
Subject(s) - biology , escherichia coli , transfer rna , heterologous , biochemistry , missense mutation , protein biosynthesis , tryptophan synthase , mutant , elongation factor , ribosome , gene , mutation , rna
Two types of aspartyl-tRNA synthetase exist: the discriminating enzyme (D-AspRS) forms only Asp-tRNA(Asp), while the nondiscriminating one (ND-AspRS) also synthesizes Asp-tRNA(Asn), a required intermediate in protein synthesis in many organisms (but not in Escherichia coli). On the basis of the E. coli trpA34 missense mutant transformed with heterologous ND-aspS genes, we developed a system with which to measure the in vivo formation of Asp-tRNA(Asn) and its acceptance by elongation factor EF-Tu. While large amounts of Asp-tRNA(Asn) are detrimental to E. coli, smaller amounts support protein synthesis and allow the formation of up to 38% of the wild-type level of missense-suppressed tryptophan synthetase.