The zinc finger is a protein domain that imparts specific nucleic acid-binding activity on a wide range of functionally important proteins. In this paper we report the molecular cloning and characterization of a novel murine zinc-finger gene, mZ13. Analysis of mZ13 cDNAs revealed that the gene expresses a 794-amino-acid protein encoded by a 2.7 kb transcript. The protein has an unusual arrangement of 13 zinc fingers into a 'hand' of 12 tandem fingers and a single isolated finger near the C-terminus. This structural organization is conserved with the probable chicken homologue, cZ13. mZ13 also contained an additional domain at the N-terminus which has previously been implicated in the regulation of zinc-finger transcription factor DNA-binding, via protein-protein interactions. mZ13 expression was detected in a wide range of murine embryonic and adult tissues. The structural organization of mZ13 and its expression profile suggest that it may function as a housekeeping DNA-binding protein that regulates the expression of specific genes.