Reverse transcriptases can clamp together nucleic acids strands with two complementary bases at their 3'-termini for initiating DNA synthesis.

ABSTRACT: We present evidence that the reverse transcriptase (RT) of human immunodeficiency virus type-1 stabilizes in vitro very short (2-nt) duplexes of 3'-overhangs of the primer strand that are annealed to complementary dinucleotides tails of DNA or RNA template strands, provided that these sequences contain at least one C or G. This RT-induced strand 'clamping' activity promotes RT-directed DNA synthesis. This function is achieved only when the functional template strand is adjacent to a second DNA or RNA segment, annealed upstream to most of the primer (without gaps). The combined clamp/polymerase activity is typical to RTs, as it was found in different RTs from diverse retroviral groups, whereas cellular DNA-polymerases (devoid of 3'→5' exonucleolytic activity) showed no clamp activity. The c

SUBMITTER: Oz-Gleenberg I 

PROVIDER: S-EPMC3035444 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature