Protein synthesis in Escherichia coli with mischarged tRNA.
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.
Min
Bokkee
B
Department of Molecular Biophysics, Yale University, New Haven, Connecticut 06520-8114, USA.
Kitabatake
Makoto
M
Polycarpo
Carla
C
Pelaschier
Joanne
J
Raczniak
Gregory
G
Ruan
Benfang
B
Kobayashi
Hiroyuki
H
Namgoong
Suk
S
Söll
Dieter
D
D001226:Aspartate-tRNA Ligase / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000096:biosynthesis*; D020125:Mutation, Missense; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics; D014169:Transformation, Bacterial; D014364:Tryptophan / Q000378:metabolism; D014367:Tryptophan Synthase / Q000235:genetics / Q000378:metabolism
D029968:Escherichia coli Proteins; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial; D012346:RNA, Transfer, Amino Acyl; D014364:Tryptophan; D012343:RNA, Transfer; D014367:Tryptophan Synthase; D001226:Aspartate-tRNA Ligase; C029194:asparaginyl-tRNA synthetase