The stages of CRISPR immunity for each of the three major types of adaptive immunity . ( 1 ) Acquisition begins by recognition of invading DNA by Cas1 and Cas2 and cleavage of a protospacer . ( 2 ) The protospacer is ligated to the direct repeat adjacent to the leader sequence and ( 3 ) single strand extension repairs the CRISPR and duplicates the direct repeat.
32.
The genome is 10140 nucleotides in length excluding the poly ( A ) tail and contains a single large open reading frame encoding a 328-kilo Dalton ( kDA ) polyprotein . 5'of the central coding sequence is a 1144-nucleotide nontranslated leader sequence ( UTR ) . 3'coding sequence is a 317-nucleotide nontranslated region which is followed by a poly ( A ) tail.
33.
Further, RNase P is one of two known multiple turnover ribozymes in nature ( the other being the ribosome ), the discovery of which earned Sidney Altman and Thomas Cech the Nobel Prize in Chemistry in 1989 : in the 1970s, Altman discovered the existence of precursor tRNA with flanking sequences and was the first to characterize RNase P and its activity in processing of the 5'leader sequence of precursor tRNA . Recent findings also reveal that RNase P has a new function.
