Cloning and sequence analysis of an H(+)-ATPase-encoding gene from the human dimorphic pathogen Histoplasma capsulatum

Abstract

A gene related to the PMA1 gene from Saccharomyces cerevisiae was isolated from the pathogenic human dimorphic fungus, Histoplasma capsulatum, using fungal-specific oligodeoxyribonucleotide (oligo) probes. This gene has been given the name Hc-PMA1. The structural organization of Hc-PMA1 consists of three exons (375, 2329 and 44 bp) and two introns (115 and 116 bp). The nucleotide sequence predicts an H(+)-ATPase-related protein of 916 amino acids (aa). Comparison of the deduced aa sequence to that of Neurospora crassa and S. cerevisiae (PMA1) plasma membrane H(+)-ATPases showed a greater similarity to that from N. crassa (85% identity). Furthermore, the two introns in the Hc-PMA1 gene interrupt the coding region in the precise locations determined for two of the four N. crassa Nc-PMA introns. H. capsulatum intron 1 contains two repeat motifs, d(TA)16 and d(TG)10, each potentially capable of forming non-B DNA structures. Northern analysis of H. capsulatum total RNA indicated that the Hc-PMA1-specific mRNA is approx. 3.3 kb in size, in agreement with the predicted size of the gene.