Ontology highlight
ABSTRACT:
SUBMITTER: Das U
PROVIDER: S-EPMC4128118 | biostudies-literature | 2014 Aug
REPOSITORIES: biostudies-literature
Proceedings of the National Academy of Sciences of the United States of America 20140721 31
Many biological scenarios generate "dirty" DNA 3'-PO4 ends that cannot be sealed by classic DNA ligases or extended by DNA polymerases. The noncanonical ligase RtcB can "cap" these ends via a unique chemical mechanism entailing transfer of GMP from a covalent RtcB-GMP intermediate to a DNA 3'-PO4 to form DNA3'pp5'G. Here, we show that capping protects DNA 3' ends from resection by Escherichia coli exonucleases I and III and from end-healing by T4 polynucleotide 3' phosphatase. By contrast, the c ...[more]