Branchpoint sugar stereochemistry determines the hydrolytic susceptibility of branched RNA fragments by the yeast debranching enzyme (YDBR).
A series of branched RNAs (Y-shaped) related to yeast pre-mRNA splicing intermediates were synthesized incorporating both natural (i.e., ribose) and non-natural (i.e., arabinose, xylose and acyclic nucleoside) branchpoints in order to examine the effect of sugar conformation and phosphodiester configuration on yDBR hydrolytic efficiency. The results indicate that 2'-phosphodiester scission with yDBR occurs only with a cis-arrangement of phosphate groups at the branchpoint (i.e., ribose) thereby discriminating between all other configurations.
Carriero
Sandra
S
Department of Chemistry, McGill University, Montreal, Quebec, Canada.
Mangos
Maria M
MM
Agha
Kazim A
KA
Noronha
Anne M
AM
Damha
Masad J
MJ
D009690:Nucleic Acid Conformation; D012316:RNA Nucleotidyltransferases / Q000378:metabolism; D012326:RNA Splicing / Q000235:genetics*; D012331:RNA, Fungal / Q000737:chemistry* / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000201:enzymology
D012331:RNA, Fungal; D012316:RNA Nucleotidyltransferases; C048135:lariat debranching enzyme