Prp8: Difference between revisions

Prp8's structure can be summarized as an amalgamation of domains from a variety of proteins, each of which has been slightly modified from their conventional forms and are now unique to Prp8. The major features present in Prp8 are a proline rich region, nuclear localization signal, bromodomain, reverse transcriptase-like domain, RNase H-like domain, and finally a metalloprotease/Jab1-like domain <ref name='Prp8, the pivotal protein of the spliceosomal catalytic center evolved from a retroelement-encoded reverse transcriptase'>DOI:10.1261/rna.2396011</ref>. The proline rich region is present at the N-terminus of Prp8, approximately running from residues 5 - 78 <ref name='Prp8, the pivotal protein of the spliceosomal catalytic center evolved from a retroelement-encoded reverse transcriptase'>DOI:10.1261/rna.2396011</ref>. This proline tract is found at the N-terminus of all fungal Prp8 sequences, and two rice sequences but is absent from most other organisms <ref name='Prp8: At the heart of the spliceosome'>DOI:10.1261/rna.2220705</ref>. The proline rich region usually adopts an extended helical structure with three residues per turn <ref name='Prp8: At the heart of the spliceosome'>DOI:10.1261/rna.2220705</ref>. The [http://en.wikipedia.org/wiki/Nuclear_localization_sequence nuclear localization signal] is also at the N-terminus of the protein, extending through amino acid residues  81 - 120, and can be located in the first 500 amino acids of the majority of organisms' Prp8 sequences <ref name='Prp8: At the heart of the spliceosome'>DOI:10.1261/rna.2220705</ref>. The nuclear localization signal contains two clusters of positively charged amino acid residues which are separated by a variable region of 10 - 12 amino acids, and organisms lacking this classical signal motif usually possess an alternative within the N-terminus of their Prp8 <ref name='Prp8: At the heart of the spliceosome'>DOI:10.1261/rna.2220705</ref>.