A novel mechanism of sugar selection utilized by a human X-family DNA polymerase.
During DNA synthesis, most DNA polymerases and reverse transcriptases select against ribonucleotides via a steric clash between the ribose 2'-hydroxyl group and the bulky side chain of an active-site residue. In this study, we demonstrated that human DNA polymerase lambda used a novel sugar selection mechanism to discriminate against ribonucleotides, whereby the ribose 2'-hydroxyl group was excluded mostly by a backbone segment and slightly by the side chain of Y505. Such steric clash was further demonstrated to be dependent on the size and orientation of the substituent covalently attached at the ribonucleotide C2'-position.
Brown
Jessica A
JA
Department of Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
Fiala
Kevin A
KA
Fowler
Jason D
JD
Sherrer
Shanen M
SM
Newmister
Sean A
SA
Duym
Wade W
WW
Suo
Zucai
Z
D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D020134:Catalytic Domain / Q000235:genetics; D017124:Conserved Sequence; D004247:DNA / Q000235:genetics / Q000378:metabolism; D019951:DNA Polymerase beta / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012265:Ribonucleotides / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D011994:Recombinant Proteins; D012265:Ribonucleotides; D004247:DNA; C415367:DNA polymerase beta2; D019951:DNA Polymerase beta