A DYNEIN HEAVY-CHAIN HOMOLOG GENE IN HEXAMITA-INFLATA

A gene encoding an unusually small dynein heavy chain homologue, hDYHH , was cloned from the genome of a free-living diplomonad, Hexamita inf lata (Hi). The open reading frame (ORF) of hDYHH is 867 bp and encodes a polypeptide of 289 amino acids (aa), hDYHH. hDYHH is homologous to the region around the third P-loop ATP-binding site of several dynein heavy chain polypeptides that are around 4000 aa. Northern blot analys is showed that hDYHH is expressed in vivo and that the mRNA length (ap proximately 1.8 kb) is consistent with the gene length (1.67 kb). Sout hern blot analysis indicated that there are hDYHH homologues within th e Hi genome, possibly including a longer dynein heavy chain gene. An h DYHH homologue was also identified in Hexamita pusilla (Hp). hDYHH is the first full-length protein-encoding gene cloned from Hexamita. (C) 1998 Elsevier Science B.V.