Amino acid sequence analysis of the beta- and gamma-subunits of eukaryotic initiation factor eIF-2. Identification of regions interacting with GTP.
Biochim Biophys Acta
; 1079(3): 308-15, 1991 Sep 20.
Article
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| MEDLINE
| ID: mdl-1911855
ABSTRACT
By affinity labelling using two different GTP photoaffinity analogues we previously demonstrated that both the beta- and gamma-subunits of eukaryotic initiation factor eIF-2 are involved in GTP binding (Bommer, U.-A. and Kurzchalia, T.V. (1989) FEBS Lett. 244, 323-327). We have now applied the same method in combination with CNBr cleavage and microsequence analysis in order investigate which part of the polypeptide chain of eIF-2 beta is in close contact to the bound GTP. From the three main CNBr fragments of eIF-2 beta, the C-terminal one was found to be labelled by the applied GTP photoaffinity analogue, Guo(2',3'-TDBH)ppp. Because the cDNA sequence of the gamma-subunit of eIF-2 has not yet been published and because cDNA sequence analysis of eIF-2 beta revealed only two out of three consensus sequence elements of a GTP-binding domain, we also sequenced the CNBr fragments of eIF-2 gamma. In this way, sequences containing about 50 amino acid residues were obtained. Taken together with the recently published N-terminal sequences of tryptic peptides of eIF-2 gamma from pig liver (Suzuki et al. 1990, J. Biochem. 108, 635-641), about 30% of the total sequence is now known. One of the CNBr fragments from rabbit eIF-2 gamma contains a sequence (AXXAXXGK) which in several respects resembles that of the consensus sequence element absent from the beta-subunit.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Factor 2 Eucariótico de Iniciación
/
Guanosina Trifosfato
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
1991
Tipo del documento:
Article