Question

tRNA synthetases play a key role in protein biosynthesis by catalyzing the specific aminoacylation of tRNA at their 3' ends, a two step reaction termed "charging" of tRNA. The tutorial depicts the binding of glutaminyl-tRNA synthetase and tRNAGln. A uracil (U35) provides a key element for the recognition of tRNAGln by the synthetase enzyme. U35 of the tRNA is anchored in place by specific amino acids in the synthetase protein interacting ionically with the nearby backbone phosphates. Given what you know about ionic bonds and the phosphate backbone of RNA, what type of amino acids are involved in this interaction?

(A) Amino acids with polar uncharged side chains
(B) Amino acids with negatively charged side chains
(C) Amino acids with positively charged side chains
(D) Amino acids with hydrophobic side chains

Answer 1

Answer:

Option C) Amino acids with positively charged side chains

Explanation:

The phosphate backbone of RNA has negative charge, then it can interact ionically with positive charges from amino acids in the synthetase protein, forming a kind of pocket quite specific for t he U35 placement in the anticodon of tRNA-Gln