Unknown

Dataset Information

0

A Glimpse of the Peptide Profile Presentation by Xenopus laevis MHC Class I: Crystal Structure of pXela-UAA Reveals a Distinct Peptide-Binding Groove.


ABSTRACT: The African clawed frog, Xenopus laevis, is a model species for amphibians. Before metamorphosis, tadpoles do not efficiently express the single classical MHC class I (MHC-I) molecule Xela-UAA, but after metamorphosis, adults express this molecule in abundance. To elucidate the Ag-presenting mechanism of Xela-UAA, in this study, the Xela-UAA structure complex (pXela-UAAg) bound with a peptide from a synthetic random peptide library was determined. The amino acid homology between the Xela-UAA and MHC-I sequences of different species is <45%, and these differences are fully reflected in the three-dimensional structure of pXela-UAAg. Because of polymorphisms and interspecific differences in amino acid sequences, pXela-UAAg forms a distinct peptide-binding groove and presents a unique peptide profile. The most important feature of pXela-UAAg is the two-amino acid insertion in the ?2-helical region, which forms a protrusion of ?3.8 Å that is involved in TCR docking. Comparison of peptide-MHC-I complex (pMHC-I) structures showed that only four amino acids in ?2-microglobulin that were bound to MHC-I are conserved in almost all jawed vertebrates, and the most unique feature in nonmammalian pMHC-I molecules is that the AB loop bound ?2-microglobulin. Additionally, the binding distance between pMHC-I and CD8 molecules in nonmammals is different from that in mammals. These unique features of pXela-UAAg provide enhanced knowledge of T cell immunity and bridge the knowledge gap regarding the coevolutionary progression of the MHC-I complex from aquatic to terrestrial species.

SUBMITTER: Ma L 

PROVIDER: S-EPMC6926391 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

altmetric image

Publications

A Glimpse of the Peptide Profile Presentation by <i>Xenopus laevis</i> MHC Class I: Crystal Structure of p<i>Xela</i>-UAA Reveals a Distinct Peptide-Binding Groove.

Ma Lizhen L   Zhang Nianzhi N   Qu Zehui Z   Liang Ruiying R   Zhang Lijie L   Zhang Bing B   Meng Geng G   Dijkstra Johannes M JM   Li Shen S   Xia Max Chun MC  

Journal of immunology (Baltimore, Md. : 1950) 20191127 1


The African clawed frog, <i>Xenopus laevis</i>, is a model species for amphibians. Before metamorphosis, tadpoles do not efficiently express the single classical MHC class I (MHC-I) molecule <i>Xela</i>-UAA, but after metamorphosis, adults express this molecule in abundance. To elucidate the Ag-presenting mechanism of <i>Xela</i>-UAA, in this study, the <i>Xela</i>-UAA structure complex (p<i>Xela</i>-UAAg) bound with a peptide from a synthetic random peptide library was determined. The amino aci  ...[more]

Similar Datasets

2022-05-31 | PXD027725 | Pride
| S-EPMC5501940 | biostudies-literature
| S-EPMC4572066 | biostudies-literature
| S-EPMC9901037 | biostudies-literature
| S-EPMC7679963 | biostudies-literature
| S-EPMC4321303 | biostudies-literature
| S-EPMC10981672 | biostudies-literature
| S-EPMC4642839 | biostudies-other
| S-EPMC8106206 | biostudies-literature
| S-EPMC7590165 | biostudies-literature