Elongation factor Ts of Chlamydia trachomatis: structure of the gene and properties of the protein.
A putative structural gene cluster containing four open reading frames (ORFs) located downstream of the omp1 gene of Chlamydia trachomatis mouse pneumonitis (MoPn) was cloned and sequenced. A GenBank survey indicated that the identified cluster is similar to the rpsB-tsf-pyrH(smbA)-frr region of Escherichia coli. The second ORF was 846 bp encoding a 282-amino-acid polypeptide with a calculated M(r) 30,824. Alignment of this deduced protein sequence and E. coli elongation factor Ts (EF-Ts, product of tsf) demonstrated 34% identity and an additional 14% similarity. The putative chlamydial tsf gene was expressed in E. coli as a nonfusion protein and as a 6x His-tagged fusion protein. By SDS-PAGE analysis, the molecular weights of the nonfusion recombinant protein and a protein of chlamydial elementary bodies (EBs), which was recognized by monoclonal antibodies derived from the nonfusion recombinant protein, are 34 kDa. The purified recombinant 6x His-tagged fusion protein increased the rate of GDP exchange with both Chlamydia and E. coli elongation factor Tu (EF-Tu). These data show that the second gene of the identified cluster is tsf. Unlike EF-Ts from any other species, its activity was comparable to that of E. coli EF-Ts in exchange reaction with E. coli EF-Tu.
Zhang
Y
Y
Maxwell Finland Laboratory for Infectious Diseases, Boston Medical Center, Boston University School of Medicine, Massachusetts 02118, USA. yxzhang@acs.bu.edu
Tao
J
J
Zhou
M
M
Meng
Q
Q
Zhang
L
L
Shen
L
L
Klein
R
R
Miller
D L
DL
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015153:Blotting, Western; D002692:Chlamydia trachomatis / Q000235:genetics*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial; D006153:Guanosine Diphosphate / Q000378:metabolism; D008969:Molecular Sequence Data; D010444:Peptide Elongation Factor Tu / Q000378:metabolism; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D010445:Peptide Elongation Factors; D011994:Recombinant Proteins; C023512:elongation factor Ts; D006153:Guanosine Diphosphate; D010444:Peptide Elongation Factor Tu