Exon--Intron Organization and Complete Nucleotide Sequence of a Human Major Histocompatibility Antigen DCβ Gene
We have determined the complete nucleotide sequence of a human class II histocompatibility antigen DCβ gene. The gene spans more than 7 kilobases and contains five exons corresponding to the different domains of the DCβ polypeptide. The exon-intron organization is thus analogous to that of class II...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 80; no. 23; pp. 7313 - 7317 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences of the United States of America
01.12.1983
National Acad Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | We have determined the complete nucleotide sequence of a human class II histocompatibility antigen DCβ gene. The gene spans more than 7 kilobases and contains five exons corresponding to the different domains of the DCβ polypeptide. The exon-intron organization is thus analogous to that of class II antigen α -chain genes, class I antigen heavy chain genes, and the constant parts of immunoglobulin genes, emphasizing further the evolutionary relationship among these molecules. The mature polypeptide deduced from the DCβ gene shows 93% and 88% homology, respectively, to sequences derived from two DCβ cDNA clones of other haplotypes. The allelic polymorphism of DCβ chains resides predominantly in the first extracellular domain, whereas the rest of the polypeptide is virtually constant. The exons of the DCβ gene display high homology to the corresponding exons of a murine I-Aβ gene. Also, the introns show significant homology. The DCβ chains lack eight amino acids in the cytoplasmic tail, as compared to DR and I-A β chains. This is probably due to a nonfunctional splice junction of DCβ genes, causing a separate cytoplasmic exon to be nonexpressed. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.80.23.7313 |