Chapter 21 Ribozymes-catalytic RNA molecules

first catalytic RNA discovered

rRNA precursor

how does Rnase P RNP work

contains ncRNA that functions as catalytic center, processing 5’ end of tRNA

important ribozyme features

individual bases at specific positions, sugar phsophate backbones, secondary feature

Group I introns

self splicing, use guanosine in active site, metal ions, in secondary structure two exons located around active site allowing for splicing reactions

Rnase P

catalytic subunit entirely RNA, binds to tRNA and completes catalytic reaction

RNase P requires for cleavage

Mg2+

Diels-alderase ribozyme

reaction establishes two new C-C bonds

Hammerhead ribozymes

self-cleaving RNAs that contain hammerhead motif, naturally occuring in plants

What does hammerhead self-cleavage generate

2’,3’ cyclic phosphate and a 5’OH

glmS ribozyme

associates with glucosamine-6-phosphate which binds to active site and self cleaves, glmS gene requires for glucosamine-6-phosphate production, changes depending on glmS function