Human DNA polymerase α in binary complex with a DNA

DNA template-primer

Javier Coloma, Robert E. Johnson, Louise Prakash, Satya Prakash, Aneel K. Aggarwal

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The Polα/primase complex assembles the short RNA-DNA fragments for priming of lagging and leading strand DNA replication in eukaryotes. As such, the Polα polymerase subunit encounters two types of substrates during primer synthesis: an RNA:DNA helix and a DNA:DNA helix. The engagement of the polymerase subunit with the DNA:DNA helix has been suggested as the of basis for primer termination in eukaryotes. However, there is no structural information on how the Polα polymerase subunit actually engages with a DNA:DNA helix during primer synthesis. We present here the first crystal structure of human Polα polymerase subunit in complex with a DNA:DNA helix. Unexpectedly, we find that portion of the DNA:DNA helix in contact with the polymerase is not in a B-form but in a hybrid A-B form. Almost all of the contacts observed previously with an RNA primer are preserved with a DNA primer-with the same set of polymerase residues tracking the sugar-phosphate backbone of the DNA or RNA primer. Thus, rather than loss of specific contacts, the free energy cost of distorting DNA from B-to hybrid A-B form may augur the termination of primer synthesis in eukaryotes.

Original languageEnglish (US)
Article number23784
JournalScientific Reports
Volume6
DOIs
StatePublished - Apr 1 2016

Fingerprint

DNA Primers
DNA-Directed DNA Polymerase
DNA
Eukaryota
DNA Primase
Sugar Phosphates
DNA Replication

ASJC Scopus subject areas

  • General

Cite this

Human DNA polymerase α in binary complex with a DNA : DNA template-primer. / Coloma, Javier; Johnson, Robert E.; Prakash, Louise; Prakash, Satya; Aggarwal, Aneel K.

In: Scientific Reports, Vol. 6, 23784, 01.04.2016.

Research output: Contribution to journalArticle

@article{e48b19c7b9ac47b9b8378b4323634a64,
title = "Human DNA polymerase α in binary complex with a DNA: DNA template-primer",
abstract = "The Polα/primase complex assembles the short RNA-DNA fragments for priming of lagging and leading strand DNA replication in eukaryotes. As such, the Polα polymerase subunit encounters two types of substrates during primer synthesis: an RNA:DNA helix and a DNA:DNA helix. The engagement of the polymerase subunit with the DNA:DNA helix has been suggested as the of basis for primer termination in eukaryotes. However, there is no structural information on how the Polα polymerase subunit actually engages with a DNA:DNA helix during primer synthesis. We present here the first crystal structure of human Polα polymerase subunit in complex with a DNA:DNA helix. Unexpectedly, we find that portion of the DNA:DNA helix in contact with the polymerase is not in a B-form but in a hybrid A-B form. Almost all of the contacts observed previously with an RNA primer are preserved with a DNA primer-with the same set of polymerase residues tracking the sugar-phosphate backbone of the DNA or RNA primer. Thus, rather than loss of specific contacts, the free energy cost of distorting DNA from B-to hybrid A-B form may augur the termination of primer synthesis in eukaryotes.",
author = "Javier Coloma and Johnson, {Robert E.} and Louise Prakash and Satya Prakash and Aggarwal, {Aneel K.}",
year = "2016",
month = "4",
day = "1",
doi = "10.1038/srep23784",
language = "English (US)",
volume = "6",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",

}

TY - JOUR

T1 - Human DNA polymerase α in binary complex with a DNA

T2 - DNA template-primer

AU - Coloma, Javier

AU - Johnson, Robert E.

AU - Prakash, Louise

AU - Prakash, Satya

AU - Aggarwal, Aneel K.

PY - 2016/4/1

Y1 - 2016/4/1

N2 - The Polα/primase complex assembles the short RNA-DNA fragments for priming of lagging and leading strand DNA replication in eukaryotes. As such, the Polα polymerase subunit encounters two types of substrates during primer synthesis: an RNA:DNA helix and a DNA:DNA helix. The engagement of the polymerase subunit with the DNA:DNA helix has been suggested as the of basis for primer termination in eukaryotes. However, there is no structural information on how the Polα polymerase subunit actually engages with a DNA:DNA helix during primer synthesis. We present here the first crystal structure of human Polα polymerase subunit in complex with a DNA:DNA helix. Unexpectedly, we find that portion of the DNA:DNA helix in contact with the polymerase is not in a B-form but in a hybrid A-B form. Almost all of the contacts observed previously with an RNA primer are preserved with a DNA primer-with the same set of polymerase residues tracking the sugar-phosphate backbone of the DNA or RNA primer. Thus, rather than loss of specific contacts, the free energy cost of distorting DNA from B-to hybrid A-B form may augur the termination of primer synthesis in eukaryotes.

AB - The Polα/primase complex assembles the short RNA-DNA fragments for priming of lagging and leading strand DNA replication in eukaryotes. As such, the Polα polymerase subunit encounters two types of substrates during primer synthesis: an RNA:DNA helix and a DNA:DNA helix. The engagement of the polymerase subunit with the DNA:DNA helix has been suggested as the of basis for primer termination in eukaryotes. However, there is no structural information on how the Polα polymerase subunit actually engages with a DNA:DNA helix during primer synthesis. We present here the first crystal structure of human Polα polymerase subunit in complex with a DNA:DNA helix. Unexpectedly, we find that portion of the DNA:DNA helix in contact with the polymerase is not in a B-form but in a hybrid A-B form. Almost all of the contacts observed previously with an RNA primer are preserved with a DNA primer-with the same set of polymerase residues tracking the sugar-phosphate backbone of the DNA or RNA primer. Thus, rather than loss of specific contacts, the free energy cost of distorting DNA from B-to hybrid A-B form may augur the termination of primer synthesis in eukaryotes.

UR - http://www.scopus.com/inward/record.url?scp=84971351761&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84971351761&partnerID=8YFLogxK

U2 - 10.1038/srep23784

DO - 10.1038/srep23784

M3 - Article

VL - 6

JO - Scientific Reports

JF - Scientific Reports

SN - 2045-2322

M1 - 23784

ER -