Assignment and ordering of twenty-three unique NotI-linking clones containing expressed genes including the guanosine 5'-monophosphate synthetase gene to human chromosome 3.

Twenty-three unique NotI-linking clones, mainly isolated from the NRL1 library, were mapped and ordered by fluorescence in situ hybridization to human chromosome 3. All these clones were partially sequenced around the NotI sites and thus represent sequence-tagged sites. The EMBL nucleotide database was then searched with sequences from the NotI-linking clones using the FASTA program. This search revealed that the NRL-090 clone (at 3q24) contains the gene encoding human guanosine 5'-monophosphate synthetase (GMPS-PEN). To our knowledge, this is the first localization of this gene. Clone NL1-320 (at 3p21.3) contains a gene encoding arginine tRNA (97.3% identity in 73 bp), while clones NRL-063, NRL-097 and NRL-143 contain expressed sequences with unknown functions. Other clones displayed 60-85% similarities to cDNAs, CpG islands and other genes.