A gradient of template dependence defines distinct biological roles for family X polymerases in nonhomologous end joining

Stephanie A Nick McElhinny; Jody M Havener; Miguel Garcia-Diaz; Raquel Juárez; Katarzyna Bebenek; Barbara L Kee; Luis Blanco; Thomas A Kunkel; Dale A Ramsden

doi:10.1016/j.molcel.2005.06.012

A gradient of template dependence defines distinct biological roles for family X polymerases in nonhomologous end joining

Mol Cell. 2005 Aug 5;19(3):357-66. doi: 10.1016/j.molcel.2005.06.012.

Authors

Stephanie A Nick McElhinny¹, Jody M Havener, Miguel Garcia-Diaz, Raquel Juárez, Katarzyna Bebenek, Barbara L Kee, Luis Blanco, Thomas A Kunkel, Dale A Ramsden

Affiliation

¹ Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.

PMID: 16061182
DOI: 10.1016/j.molcel.2005.06.012

Abstract

Three Pol X family members have been linked to nonhomologous end joining (NHEJ) in mammals. Template-independent TdT promotes diversity during NHEJ-dependent repair of V(D)J recombination intermediates, but the roles of the template-dependent polymerases mu and lambda in NHEJ remain unclear. We show here that pol mu and pol lambda are similarly recruited by NHEJ factors to fill gaps when ends have partially complementary overhangs, suggesting equivalent roles promoting accuracy in NHEJ. However, only pol mu promotes accuracy during immunoglobulin kappa recombination. This distinctive in vivo role correlates with the TdT-like ability of pol mu, but not pol lambda, to act when primer termini lack complementary bases in the template strand. However, unlike TdT, synthesis by pol mu in this context is primarily instructed by a template from another DNA molecule. This apparent gradient of template dependence is largely attributable to a small structural element that is present but different in all three polymerases.

Publication types

Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

MeSH terms

Amino Acid Sequence
Animals
B-Lymphocytes / metabolism
Cell Line
DNA / genetics
DNA / metabolism
DNA Nucleotidylexotransferase / genetics
DNA Nucleotidylexotransferase / metabolism
DNA Polymerase beta / genetics
DNA Polymerase beta / metabolism*
DNA Repair
DNA-Directed DNA Polymerase / genetics
DNA-Directed DNA Polymerase / metabolism*
Gene Expression / genetics
Gene Rearrangement / genetics
Humans
Immunoglobulin Joining Region / genetics*
Immunoglobulin kappa-Chains / genetics*
Mice
Models, Molecular
Molecular Sequence Data
Recombinant Proteins / metabolism
Recombination, Genetic / genetics*
Sequence Homology, Amino Acid
Substrate Specificity
Templates, Genetic
Transfection

Substances

Immunoglobulin Joining Region
Immunoglobulin kappa-Chains
Recombinant Proteins
DNA
DNA polymerase beta2
DNA polymerase mu
DNA Nucleotidylexotransferase
DNA Polymerase beta
DNA-Directed DNA Polymerase

Grants and funding

CA097096/CA/NCI NIH HHS/United States