The murine histidyl-tRNA synthetase-encoding gene (MMHRS) coding region has been cloned and sequenced. The 1527-bp transcript shows a strikingly similar structural organization to that of its human counterpart, particularly within the three class II aminoacyl-tRNA synthetase structural motifs and the two histidyl-tRNA synthetase signature regions. It is predicted, as in humans, to have a coiled-coil alpha-helical structure that is characteristic of many autoantigens. MMHRS shows some degree of polymorphism at both the DNA and amino-acid levels, although its sequence is well conserved amongst the commonly used laboratory mouse strains.