The Human Major Histocompatibility Complex: 42,221 bp of Genomic Sequence, High-Density Sequence-Tagged Site Map, Evolution, and Polymorphism for HLA Class I

Genomics ◽  
1998 ◽  
Vol 51 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Marta Janer ◽  
Daniel E. Geraghty
Keyword(s):  
Major Histocompatibility Complex ◽  
Genomic Sequence ◽  
Hla Class I ◽  
High Density ◽  
Class I ◽  
Major Histocompatibility ◽  
Human Major Histocompatibility Complex ◽  
Sequence Tagged Site ◽  
Histocompatibility Complex

scholarly journals Different Evolutionary Histories in Two Subgenomic Regions of the Major Histocompatibility Complex

1999 ◽  
Vol 9 (6) ◽  
pp. 541-549 ◽  
Author(s):  
Silvana Gaudieri ◽  
Jerzy K. Kulski ◽  
Roger L. Dawkins ◽  
Takashi Gojobori
Keyword(s):  
Major Histocompatibility Complex ◽  
Homologous Recombination ◽  
Hla Class I ◽  
Gene Families ◽  
Class I ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Multicopy Gene ◽  
History Of ◽  
The Common

Two subgenomic regions within the major histocompatibility complex, the alpha and beta blocks, contain members of the multicopy gene families HLA class I, human endogenous retroviral sequence (HERV-16; previously known as P5 and PERB3), hemochromatosis candidate genes (HCG) (II, IV, VIII, IX), 3.8-1, and MIC (PERB11). In this study we show that the two blocks consist of imperfect duplicated segments, which contain linked members of the different gene families. The duplication and truncation sites of the segments are associated with retroelements. The retroelement sites appear to generate the imperfect duplications, insertions/deletions, and rearrangements, most likely via homologous recombination. Although the two blocks share several characteristics, they differ in the number and orientation of the duplicated segments. On the 62.1 haplotype, the alpha block consists of at least 10 duplicated segments that predominantly contain pseudogenes and gene fragments of the HLA class I and MIC (PERB11) gene families. In contrast, the beta block has two major duplications containing the genes HLA-B and HLA-C, and MICA(PERB11.1) and MICB(PERB11.2). Given the common origin between the blocks, we reconstructed the duplication history of the segments to understand the processes involved in producing the different organization in the two blocks. We then found that the beta block contains four distinct duplications from two separate events, whereas the alpha block is characterized by multisegment duplications. We will discuss these results in relation to the genetic content of the two blocks.

scholarly journals Evidence that gene G7a in the human major histocompatibility complex encodes valyl-tRNA synthetase

1991 ◽  
Vol 278 (3) ◽  
pp. 809-816 ◽  
Author(s):  
S L Hsieh ◽  
R D Campbell
Keyword(s):  
Major Histocompatibility Complex ◽  
Amino Acid ◽  
Molecular Mass ◽  
Trna Synthetase ◽  
Class I ◽  
Major Histocompatibility ◽  
High Sequence Identity ◽  
Human Major Histocompatibility Complex ◽  
Trna Synthetases ◽  
Histocompatibility Complex

At least 36 genes have now been located in a 680 kb segment of DNA between the class I and class II multigene families within the class III region of the human major histocompatibility complex on chromosome 6p21.3. The complete nucleotide sequence of the 4.3 kb mRNA of one of these genes, G7a (or BAT6), has been determined from cDNA and genomic clones. The single-copy G7a gene encodes a 1265-amino-acid protein of molecular mass 140,457 Da. Comparison of the derived amino acid sequence of the G7a protein with the National Biomedical Research Foundation protein databases revealed 42% identity in a 250-amino-acid overlap with Bacillus stearothermophilus valyl-tRNA synthetase, 38.0% identity in a 993-amino-acid overlap with Escherichia coli valyl-tRNA synthetase (val RS), and 48.3% identity in a 1043-amino-acid overlap with Saccharomyces cerevisiae valyl-tRNA synthetase. The protein sequence of G7a contains two short consensus sequences, His-Ile-Gly-His and Lys-Met-Ser-Lys-Ser, which is the typical signature structure of class I tRNA synthetases and indicative of the presence of the Rossman fold. In addition, the molecular mass of the G7a protein is the same as that of other mammalian valyl-tRNA synthetases. These features and the high sequence identity with yeast valyl-tRNA synthetase strongly support the fact that the G7a gene, located within the major histocompatibility complex, encodes the human valyl-tRNA synthetase.

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