Protein splicing: an analysis of the branched intermediate and its resolution by succinimide formation.
Protein splicing involves the excision of an internal domain from a precursor protein and the ligation of the external domains so as to generate two new proteins. Study of this process has recently been facilitated by the isolation of a precursor and a branched intermediate from a thermophilic protein splicing element expressed in a foreign protein context. Two aspects of protein splicing are examined in this paper. We demonstrate a succinimide at the C-terminus of the spliced internal protein, implicating cyclization of asparagine in resolution of the branched intermediate, and we identify an alkali-labile bond in the branched intermediate. A revised protein splicing model based on these experimental results is presented.
Xu
M Q
MQ
New England Biolabs, Inc., Beverly, MA 01915.
Comb
D G
DG
Paulus
H
H
Noren
C J
CJ
Shao
Y
Y
Perler
F B
FB
D000468:Alkalies; D000595:Amino Acid Sequence; D001483:Base Sequence; D017124:Conserved Sequence; D017931:DNA Primers; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013388:Succinimides / Q000378:metabolism*
D000468:Alkalies; D017931:DNA Primers; D011506:Proteins; D013388:Succinimides; C032620:succinimide