caa a22 4500 467907439 CHVBK 20180406152838.0 cr unu---uuuuu 170328e20060601xx s 000 0 eng 10.1007/s00251-006-0114-5 doi (NATIONALLICENCE)springer-10.1007/s00251-006-0114-5 Polymorphism, natural selection, and structural modeling of class Ia MHC in the African clawed frog ( Xenopus laevis ) [Elektronische Daten] [D. Bos, B. Waldman] In the African clawed frog (Xenopus laevis), two deeply divergent allelic lineages of multiple genes of the class I MHC region have been discovered. For the MHC class I UAA locus, functional differences and the molecular basis for lineages maintenance are unknown. Alleles of linked class I region genes also exhibit strong disequilibrium with specific MHC alleles, but the underlying cause is not clear. We use MHC class Ia sequence data to estimate substitution rates and investigate structural differences between allelic lineages from protein models. Results indicate the operation of natural selection, and differences in the steric properties in the F pocket of the peptide-binding region among lineages. Variability in this pocket likely enables allelic lineages to bind very different sets of peptides and to interact differently with MHC chaperones in the endoplasmic reticulum. These results constitute evidence of the molecular evolutionary basis for 1) the maintenance of allelic lineages, 2) functional differences among lineages, and 3) strong linkage disequilibrium of allelic variants of class I region genes in X. laevis. Springer-Verlag, 2006 Functional divergence nationallicence MHC nationallicence Peptide-binding region nationallicence Allelic lineages nationallicence F pocket nationallicence Bos D. School of Biological Sciences, University of Canterbury, Christchurch, New Zealand aut Waldman B. School of Biological Sciences, University of Canterbury, Christchurch, New Zealand aut Immunogenetics Springer-Verlag 58/5-6(2006-06-01), 433-442 0093-7711 58:5-6<433 2006 58 251 https://doi.org/10.1007/s00251-006-0114-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00251-006-0114-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bos D. School of Biological Sciences, University of Canterbury, Christchurch, New Zealand aut NATIONALLICENCE 700 1- Waldman B. School of Biological Sciences, University of Canterbury, Christchurch, New Zealand aut NATIONALLICENCE 773 0- Immunogenetics Springer-Verlag 58/5-6(2006-06-01), 433-442 0093-7711 58:5-6<433 2006 58 251 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer