Intron Splicing Group I Part 1/2
Group I Intron Splicing (part 1). Intron splicing has three phases: 1. Spliceosome assembly pathway Unlike Group I and Group II introns, pre-mRNA introns are not able to self-splice without the assistance of trans- acting RNA or protein factors. Splicing of precursor messenger RNA takes place in the spliceosome, a large (~60S) RNA/protein macromolecular machine assembles de novo at each round of splicing. The spliceosomal machinery is complex and formed from five ribonucleoprotein subunits, termed uridine-rich small nuclear nucleoproteins (U1, U2, U4, U5, U6 snRNPs), transiently associated to more than 70 non-snRNPs splicing factors (RNA helicases, SR splicing factors, etc...). The detailed mechanism of spliceosome assembly is complex. 2. Splicing reactions and 3 Ultimate step: Intron release. Read more: http://webcache.googleusercontent.com/search?q=cache:CQChA3U9V6cJ:mips.helmholtz-muenchen.de/proj/yeast/reviews/intron/spliceo_splicing.html+Intron+Splicing&cd=7&hl=en&ct=clnk&gl=us
