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Disruption of substrate binding site in E. coli RNA polymerase by lethal alanine substitutions in carboxy terminal domain of the β subunit
Author(s) -
Polyakov Andrey,
Nikiforov Vadim,
Goldfarb Alex
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00060-5
Subject(s) - alanine , protein subunit , specificity factor , rna polymerase , binding site , polymerase , biochemistry , enzyme , biology , microbiology and biotechnology , chemistry , substrate (aquarium) , amino acid , rna , stereochemistry , rna dependent rna polymerase , gene , ecology
Alanine substitution of four amino acids in two evolutionarily conserved motifs, PSRM and RFGEME, near the carboxy terminus of the β subunit of E. coli RNA polymerase results in a dramatic loss of the enzyme's affinity to substrates with no apparent effect on the maximal rate of the enzymatic reaction or on binding to promoters. The magnitude and selectivity of the effect suggest that the mutations disrupt the substrate binding site of the active center.