ISSN:
1432-1211
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Five class II (B-L) B genes are encoded in the major histocompatibility complex (MHC) of chickens of the B 12 haplotype. We report here the nucleotide sequence of one of these genes, B-LBII, as well as the primary structure of a corresponding cDNA. The organization of B-LBII, its 5' flanking region including the promotor region, and the amino acid sequence of its product are compared to mammalian class II B genes and to the previously described B-LBIII gene, which probably is a pseudogene since no B-LBIII transcript could be identified. The 5' flanking oegion of B-LBII exhibits homologs of transcription-controlling sequence motifs, namely S, X, X2, and Y boxes, of class II A and B genes of rodents and man. However, the promotor region of B-LBIII lacks an equivalent of the S box, displays two nucleic acid substitutions in the core sequence of the Y box, exhibits a 16 base pair (bp) deletion upstream of the site of initiation of transcription. Therefore, an aberrant promotor region is likely to account for the pseudogene-like nature of B-LBIII, which displays open-reading frames in all exons. The data obtained with the functional B-LBII gene are in line with our previous interpretation that both genomic organization and tertiary structure of class II β molecules are remarkably conserved between birds and mammals.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00211553
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