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Spontaneous C‐cleavage of a mini‐intein without its conserved N‐terminal motif A
Author(s) -
Qi Xingmei,
Meng Qing,
Liu Xiang-Qin
Publication year - 2011
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2011.06.035
Subject(s) - intein , protein splicing , cleavage (geology) , chemistry , rna splicing , stereochemistry , genetics , biology , biochemistry , gene , paleontology , rna , fracture (geology)
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.