Protein
Intron-encoded RNA maturase bI4
Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
Function
Mitochondrial mRNA maturase required for splicing of intron 4 of the cytochrome b (COB) gene, containing its own coding sequence, and intron 4 in COX1, coding for the related homing endonuclease aI4. In vivo splicing requires in addition the imported mitochondrial leucyl-tRNA synthetase NAM2. Both proteins seem to stimulate the intrinsic ribozyme activity of intron bI4 through binding to and stabilizing specific secondary and tertiary structure elements in the RNA.
Similarity
In the C-terminal section; belongs to the LAGLIDADG endonuclease family.
Sequence
MAFRKSNVYLSLVNSYIIDSPQPSSINYWWNMGSLLGLCLVIQIVTGIFMAMHYSSNIELAFSSVEHIMRDVHNGYILRYLHANGASFFFMVMFMHMAKGLYYGSYRSPRVTLWNVGVIIFILTIATAFLGYCCVYGQMSHWGATVITNLFSAIPFVGNDIVSWLWGGFSVSNPTIQRFFALHYLVPFIIAAMVIMHLMALHIHGSSNPLGITGNLDRIPMHSYFIFKDLVTVFLFMLILALFVFYSPNTLGQNMALLLITYVINILCAVCWKSLFIKYQWKIYNKTTYYFIIQNILNTKQLNNFVLKFNWTKQYNKMNIVSDLFNPNRVKYYYKEDNQQVTNMNSSNTHLTSNKKNLLVDTSETTRTTKNKFNYLLNIFNMKKMNQIITKRHYSIYKDSNIRFNQWLAGLIDGDGYFCITKNKYASCEITVELKDEKMLRQIQDKFGGSVKLRSGVKAIRYRLQNKEGMIKLINAVNGNIRNSKRLVQFNKVCILLNIDFKEPIKLTKDNAWFMGFFDADGTINYYYSGKLKIRPQLTISVTNKYLHDVEYYREVFGGNIYFDKAKNGYFKWSINNKELHNIFYTYNKSCPSKSNKGKRLFLIDKFYYLYDLLAFKAPHNTALYKAWLKFNEKWNNN