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- ********************************************
- * GTP-binding elongation factors signature *
- ********************************************
-
- Elongation factors [1,2] are proteins catalyzing the elongation of peptide
- chains in protein biosynthesis. In both prokaryotes and eukaryotes, there are
- three distinct types of elongation factors, as described in the following
- table:
-
- ---------------------------------------------------------------------------
- Eukaryotes Prokaryotes Function
- ---------------------------------------------------------------------------
- EF-1alpha EF-Tu Binds GTP and an aminoacyl-tRNA; delivers the
- latter to the A site of ribosomes.
- EF-1beta EF-Ts Interacts with EF-1a/EF-Tu to displace GDP and
- thus allows the regeneration of GTP-EF-1a.
- EF-2 EF-G Binds GTP and peptidyl-tRNA and translocates the
- latter from the A site to the P site.
- ---------------------------------------------------------------------------
-
- The GTP-binding elongation factor family also includes the following proteins:
-
- - The yeast omnipotent nonsense codons suppressor protein SUP2 (also known as
- SUP35, SUF12 or GST1), highly similar to EF-1alpha [3]. A human homolog,
- GST1-Hs [4], is probably involved the regulation of cell growth.
- - Yeast HBS1 [5].
- - Rat statin S1 [6], a protein of unknown function which is highly similar to
- EF-1alpha.
- - Escherichia coli selenocysteine-specific elongation factor selB [7], which
- seems to replace EF-Tu for the insertion of selenocysteine directed by the
- UGA codon.
- - Escherichia coli peptide chain release factor 3 (RF-3) (gene prfC).
- - The tetracycline resistance proteins tetM/tetO [8,9] from various bacteria
- such as Campylobacter jejuni, Enterococcus faecalis, Streptococcus mutans
- and Ureaplasma urealyticum. Tetracycline binds to the prokaryotic ribosomal
- 30S subunit and inhibits binding of aminoacyl-tRNAs. These proteins abolish
- the inhibitory effect of tetracycline on protein synthesis.
- - The Rhizobium nodulation protein nodQ [10].
- - Escherichia coli hypothetical protein yihK [11].
-
- In EF-1-alpha, a specific region has been shown [12] to be involved in a
- conformational change mediated by the hydrolysis of GTP to GDP. This region is
- conserved in both EF-1alpha/EF-Tu as well as EF-2/EF-G and thus seems typical
- for GTP-dependent proteins which bind non-initiator tRNAs to the ribosome. The
- pattern we developed for this family of proteins include that conserved
- region.
-
- -Consensus pattern: D-x(4)-E-x(3)-[GC]-x-T-[IV]
- -Sequences known to belong to this class detected by the pattern: ALL, except
- for five different elongation factors from various sources.
- -Other sequence(s) detected in SWISS-PROT: 28.
- -Last update: June 1994 / Text revised.
-
- [ 1] Concise Encyclopedia Biochemistry, Second Edition, Walter de Gruyter,
- Berlin New-York (1988).
- [ 2] Moldave K.
- Annu. Rev. Biochem. 54:1109-1149(1985).
- [ 3] Surguchov A.P.
- Trends Biochem. Sci. 13:120-123(1988).
- [ 4] Hoshino S.-I., Miyazawa H., Enomoto T., Hanaoka F., Kikuchi A., Ui M.
- EMBO J. 8:3807-3814(1989).
- [ 5] Nelson R.J., Ziegelhoffer T., Nicolet C., Werner-Washburne M., Craig E.A.
- Cell 71:97-105(1992).
- [ 6] Ann D.K., Moutsatsos I.K., Nakamura T., Lin H.H., Mao P.-L., Lee M.-J.,
- Chin S., Liem R.K.H., Wang E.
- J. Biol. Chem. 266:10429-10437(1991).
- [ 7] Forchammer K., Leinfeldr W., Bock A.
- Nature 342:453-456(1989).
- [ 8] Manavathu E.K., Hiratsuka K., Taylor D.E.
- Gene 62:17-26(1988).
- [ 9] Leblanc D.J., Lee L.N., Titmas B.M., Smith C.J., Tenover F.C.
- J. Bacteriol. 170:3618-3626(1988).
- [10] Cervantes E., Sharma S.B., Maillet F., Vasse J., Truchet G., Rosenberg C.
- Mol. Microbiol. 3:745-755(1989).
- [11] Plunkett G. III, Burland V.D., Daniels D.L., Blattner F.R.
- Nucleic Acids Res. 21:3391-3398(1993).
- [12] Moller W., Schipper A., Amons R.
- Biochimie 69:983-989(1987).
-