1kdh
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| , resolution 3.00Å | |||||||
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| Ligands: | , , | ||||||
| Activity: | DNA nucleotidylexotransferase, with EC number 2.7.7.31 | ||||||
| Related: | 1JMS, 1BPY, 1KEJ
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Binary Complex of Murine Terminal Deoxynucleotidyl Transferase with a Primer Single Stranded DNA
OverviewOverview
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 StructureAbout this Structure
1KDH is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
ReferenceReference
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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