Abstract
DNA-dependent RNA polymerase from E. coli is rapidly inhibited by preincubation with pyridoxal 5′-phosphate. The enzyme is not inhibited by pyridoxamine 5′-phosphate or pyridoxine. Pyridoxal is about 10 times less effective than pyridoxal 5′-phosphate. Nucleoside triphosphates but not DNA, protect the enzyme from inhibition. Spectral data from the reaction mixture and NaBH4 reduction products indicate the formation of a Schiff base between the aldehyde group of pyridoxal 5′-phosphate and amino group of the enzyme. The results show that the inhibitor is reacting with a critical amino group presumably at the nucleoside phosphate binding site of the active center of the enzyme.
Original language | English |
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Pages (from-to) | 1053-1059 |
Number of pages | 7 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 55 |
Issue number | 4 |
DOIs | |
Publication status | Published - 19 Dec 1973 |
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology