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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Das, S. K. Articles by Fujimura, R. K. Search for Related Content PubMed PubMed Citation Articles by Das, S. K. Articles by Fujimura, R. K. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 255, Issue 15, 7149-7154, Aug, 1980

Mechanism of primer-template-dependent conversion of dNTP leads to dNMP by T5 DNA polymerase

SK Das and RK Fujimura

T5 DNA polymerase catalyzes both 5' leads to 3' polymerization and 3' leads to 5' hydrolysis in a processive fashion. This knowledge has been utilized to obtain evidence indicating that the enzyme has a single primer-template binding site which can function as either polymerase or exonuclease, perhaps with the cooperation of additional or different side groups. Template-dependent conversion of dNTP leads to dNMP was observed with an excess of either primer-template or enzyme. With primer-template excess, practically all the enzymes were functional as polymerase; with enzyme excess, all primer-templates were extended during the first cycle of catalysis. These observations suggest that turnover takes place at the points of chain growth. Evidence is also provided which demonstrates that the enzyme is capable of switching its direction of catalysis from 3' leads to 5' to 5' leads to 3' without leaving the primer-template. A clear correspondence between the relative amount of hydrolysis of a terminally labeled residue on the primer and the relative amount of turnover suggests that (a) the probability of hydrolysis of a given type of residue in contact with the "active site" is constant, and (b) during each turnover episode enzyme usually takes only one step in the 3' leads to 5' direction. A simple probabilistic model of turnover is discussed.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				N. Andraos, S. Tabor, and C. C. Richardson The Highly Processive DNA Polymerase of Bacteriophage T5: ROLE OF THE UNIQUE N AND C TERMINI J. Biol. Chem., November 26, 2004; 279(48): 50609 - 50618. [Abstract] [Full Text] [PDF]