title: Spontaneous C-cleavage of a mini-intein without its conserved N-terminal motif A.
abstract: Previously, the C-terminal fragment of a split intein was known to undergo controllable C-cleavage at its C-terminus only when the N-terminal fragment of the intein was added. Here we constructed a similar split intein from the Ssp DnaX intein, but we unexpectedly observed that its C-terminal 136-aa fragment could undergo spontaneous C-cleavage without the N-terminal fragment that was up to 15 aa long and contained the conserved intein motif A. This C-cleavage activity was significantly decreased by a mutation of the conserved Thr residue in the conserved intein motif B. These findings suggest a robust intein structure in the absence of motif A and a larger role of motif B in the third step of the protein splicing mechanism.
authors: Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, PR China.
authors: Xingmei
authors: X
authors: Qi
authors: Qing
authors: Q
authors: Meng
authors: Xiang-Qin
authors: XQ
authors: Liu
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics; D006868:Hydrolysis; D047668:Inteins; D010446:Peptide Fragments; D010957:Plasmids; D019154:Protein Splicing; D014161:Transduction, Genetic
chemical_list: D010446:Peptide Fragments