HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hillcoat, B. L. Articles by Blakley, R. L. Search for Related Content PubMed PubMed Citation Articles by Hillcoat, B. L. Articles by Blakley, R. L. Social Bookmarking                      What's this?

Dihydrofolate Reductase of Streptococcus faecalis

I. PURIFICATION AND SOME PROPERTIES OF REDUCTASE FROM THE WILD STRAIN AND FROM STRAIN A

From the ¹ From the Department of Biochemistry, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia

Unfractionated extracts of an amethopterin-resistant mutant of Streptococcus faecalis contained from 10 to 100 times more dihydrofolate reductase activity than the wild strain (ATCC 8043). Extracts of the mutant strain also contained significant folate reductase, but this was not detectable in wild strain extracts. Dihydrofolate reductase has been purified 100 to 500 times from the mutant extracts and 200 to 700 times from extracts of the wild strain by a procedure involving repeated gel filtration and ammonium sulfate precipitation. The procedure also results in about 70-fold purification of folate reductase from the mutant. The purified preparation from the mutant has dihydrofolate reductase specific activity greater than that calculated for the pure enzyme obtained from mammalian sources but has about the same molecular weight (approximately 21,000) as the latter; the turnover number of the bacterial enzyme is therefore higher than that of the mammalian enzyme. Evidence is presented that more than one species of dihydrofolate reductase is present in the purified preparation from the mutant, and the significance of this multiplicity of enzyme species is discussed.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				S. Shallom, K. Zhang, L. Jiang, and P. K. Rathod Essential Protein-Protein Interactions between Plasmodium falciparum Thymidylate Synthase and Dihydrofolate Reductase Domains J. Biol. Chem., December 31, 1999; 274(53): 37781 - 37786. [Abstract] [Full Text] [PDF]