Protein splicing of PRP8 mini-inteins from species of the genus Penicillium.
Inteins are protein-intervening sequences found inside the coding region of different host proteins and are translated in-frame with them. They can self-excise through protein splicing, which ligates the host protein flanks with a peptide bond. In this study, four different species of the genus Penicillium were investigated for the presence of inteins inside the conserved splicing-factor protein PRP8. We identified 157 to 162 amino acid in-frame insertions in the PRP8 protein of Penicillium chrysogenum, Penicillium expansum, and Penicillium vulpinum (formerly Penicillium claviforme). The Penicillium PRP8 inteins are mini-inteins without a conserved endonuclease domain. We demonstrated that the PRP8 mini-inteins of P. chrysogenum, P. expansum, and P. vulpinum undergo autocatalytic protein splicing when heterologously expressed in E. coli, in a model host protein, and in a divided GFP model system. They are, thus, among the smallest known nuclear-encoded, active splicing protein elements. The GFP assay should be valuable as a screening system for protein splicing inhibitors as potential antimycotic agents and as tools for studying the mechanism of protein splicing of fungal mini-inteins.
Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780, Bochum, Germany.
Skander
S
Elleuche
Nicole
N
Nolting
Stefanie
S
Pöggeler
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D047668:Inteins / Q000502:physiology*; D008969:Molecular Sequence Data; D010407:Penicillium / Q000378:metabolism*
D005656:Fungal Proteins