Temperature-sensitive mutants identify crucial structural regions of simian virus 40 large T antigen.

AUTOR(ES)

Loeber, G

RESUMO

We have completed the cloning and sequencing of all known temperature-sensitive, amino acid substitution mutants of simian virus 40 large T antigen (tsA mutants). Surprisingly, many of the mutants isolated from distinct viral strains by different laboratories are identical. Thus, 17 independently isolated mutants represent only eight distinct genotypes. This remarkable clustering of tsA mutations in a few "hot spots" in the amino acid sequence of T antigen and the temperature-sensitive phenotypes of the mutations strongly suggest that these amino acids play crucial roles in organizing the structure of one or more functional domains. Most of the mutations are located in highly conserved regions of T antigen that correlate with DNA binding, protein-protein interactions, or ATP binding. With the exception of one mutant with a lesion in the putative ATP-binding region, all the mutants are temperature sensitive for DNA replication.

Documentos Relacionados

• Functional characterization of temperature-sensitive mutants of simian virus 40 large T antigen.
• Simian virus 40 mutants carrying two temperature-sensitive mutations.
• Replication of Chinese hamster embryo cells transformed by temperature-sensitive T-antigen mutants of simian virus 40.
• Oligomerization of simian virus 40 large T antigen is not necessarily repressed by temperature-sensitive A gene lesions.
• Temperature-Sensitive Mutants of Simian Virus 40: Infection of Permissive Cells