YAC-ASSISTED CLONING OF A PUTATIVE G-PROTEIN MAPPING TO THE MHC CLASS-I REGION

We report the successful use of whole yeast artificial chromosomes (YACs) as probes for direct positional cloning of novel expressed sequences in a given genomic fragment. The class I region of the human major histocompatibility complex, in particular the chromosomal fragment spanning the HLA-E locus, was investigated. The screening of a cDNA library with a 210-kb-long YAC clone led to the identification of a new gene, positionally conserved in the major histocompatibility complex of the mouse genome and encoding a putative GTP binding protein. Although its precise function remains unknown, the interspecies conservation of both sequence and map position suggests a regulatory or functional link with the histocompatibility cluster. © 1992 Academic Press, Inc. All rights reserved.