A consolidated classification system is described for prokaryotic and
eukaryotic N-acetyltransferases in accordance with the international r
ules for gene nomenclature, The root symbol (NAT) specifically identif
ies the genes that code for the N-acetyltransferases, and NAT loci en
coding proteins with similar function are distinguished by Arabic nume
rals, Allele characters, denoted by Arabic numbers or by a combination
of Arabic numbers and uppercase Latin letters, are separated from gen
e loci by an asterisk, and the entire gene-allele symbols are italiciz
ed, Alleles at the different NAT loci have been numbered chronologica
lly irrespective of the species of origin, For designation of genotype
s at a single NAT locus, a slash serves to separate the alleles; in p
henotype designations, which are not italicized, alleles are separated
by a comma.