Premium
Mutational analysis of mammalian poly(A) polymerase identifies a region for primer binding and catalytic domain, homologous to the family X polymerases, and to other nucleotidyltransferases.
Author(s) -
Martin G.,
Keller W.
Publication year - 1996
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1996.tb00617.x
Subject(s) - biology , polymerase , dna polymerase , primer (cosmetics) , microbiology and biotechnology , genetics , dna polymerase mu , primase , biochemistry , dna , rna , reverse transcriptase , gene , circular bacterial chromosome , chemistry , organic chemistry
We have tested deletion and substitution mutants of bovine poly(A) polymerase, and have identified a small region that overlaps with a nuclear localization signal and binds to the RNA primer. Systematic mutagenesis of carboxylic amino acids led to the identification of three aspartates that are essential for catalysis. Sequence and secondary structure comparisons of regions surrounding these aspartates with sequences of other polymerases revealed a significant homology to the palm structure of DNA polymerase beta, terminal deoxynucleotidyltransferase and DNA polymerase IV of Saccharomyces cerevisiae, all members of the family X of polymerases. This homology extends as far as cca: tRNA nucleotidyltransferase and streptomycin adenylyltransferase, an antibiotic resistance factor.