Protein Splicing of Inteins and Hedgehog Autoproteolysis: Structure, Function, and Evolution

摘要: The Mxe GyrA mini-intein represents a splicing element without DRR or core endonuclease domain. Larger inteins, like the Sce VMA intein, contain homing endonucleases. structural similarity among elements and Hh-C17 can be seen in common positioning of β strands large number residues with superimposable Cα atoms (the main chain carbon atom to which side is attached) (Figure 3Figure 3). However, there little sequence identity three proteins except for involved catalysis 1Figure 1 Figure Because their structures, Hall et al. 1997xHall, T.M.T, Porter, J.A, Young, K.E, Koonin, E.V, Beachy, P.A, Leahy, D.J. Cell. 1997; 91: 85–97Abstract | Full Text PDF PubMed Scopus (150)See all ReferencesHall 1997 proposed that inteins evolved from precursor 4Figure 4). Hint module mediates ester/thioester formation, activating linkage between second protein Other systems, such as Ntn hydrolase family, employ an acyl rearrangement activate but do not have (Hall 1997). Inteins Hh-C subsequently separate methods cleaving this bond. ability ligate two exteins acquired endonuclease. allowed spread by lateral transmission. sterol recognition region (SRR) directing addition cholesterol hedgehog signaling domain, anchoring domain cell surface. Alternatively, could invaded preexisting domain/SRR element. Several nematode domains unrelated C-terminal extensions may interact molecules other than been tentatively termed adduct regions (Beachy 1997xCold Spring Harbor Symp. Cooper, M.K, von Kessler, D.P, Park, W, Hall, D.J, J.A. Quant. Biol. pressSee ReferencesBeachy order these events speculative, including assembly. Each intein coevolved associated after independent formation. Endonucleases also lost inteins. As we understand mechanism autoproteolysis, will begin able harness cleave splice any target at will.Figure 4A Scenario Evolution Hh-CA primordial subdomain was duplicated loop exchange occurred subdomains generate module. then DNA (DRR) (ENDO) (SRR). speculative. Adapted permission al., 1997.View Large Image View Hi-Res Download PowerPoint Slide