1jms
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(New page: 200px<br /><applet load="1jms" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jms, resolution 2.36Å" /> '''Crystal Structure of...)
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Revision as of 16:15, 20 November 2007
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Crystal Structure of the Catalytic Core of Murine Terminal Deoxynucleotidyl Transferase
Overview
The crystal structure of the catalytic core of murine terminal, deoxynucleotidyltransferase (TdT) at 2.35 A resolution reveals a typical, DNA polymerase beta-like fold locked in a closed form. In addition, the, structures of two different binary complexes, one with an oligonucleotide, primer and the other with an incoming ddATP-Co(2+) complex, show that the, substrates and the two divalent ions in the catalytic site are positioned, in TdT in a manner similar to that described for the human DNA polymerase, beta ternary complex, suggesting a common two metal ions mechanism of, nucleotidyl transfer in these two proteins. The inability of TdT to, accommodate a template strand can be explained by steric hindrance at the, catalytic site caused by a long lariat-like loop, which is absent in DNA, polymerase beta. However, displacement of this discriminating loop would, be sufficient to unmask a number of evolutionarily conserved residues, which could then interact with a template DNA strand. The present, structure can be used to model the recently discovered human polymerase, mu, with which it shares 43% sequence identity.
About this Structure
1JMS is a Single protein structure of sequence from Mus musculus with MG and NA as ligands. Active as DNA nucleotidylexotransferase, with EC number 2.7.7.31 Full crystallographic information is available from OCA.
Reference
Crystal structures of a template-independent DNA polymerase: murine terminal deoxynucleotidyltransferase., Delarue M, Boule JB, Lescar J, Expert-Bezancon N, Jourdan N, Sukumar N, Rougeon F, Papanicolaou C, EMBO J. 2002 Feb 1;21(3):427-39. PMID:11823435
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