ATP binding cassette (
ABC) transporters constitute a very large and ubiquitous superfamily of
membrane proteins. They are responsible for
ATP hydrolysis driven translocation of countless substrates. Being a very old and diverse group of
proteins present in all organisms they share a common feature, which is the presence of an evolutionary conservative
nucleotide binding domain (NBD)--the engine that drives the transport. Another common domain is a transmembrane domain (TMD) which consists of several membrane-spanning helices. This part of
protein is substrate-specific, thus it is much more variable.
ABC transporters are known for driving
drug efflux in many pathogens and
cancer cells, therefore they are the subject of extensive studies. There are many examples of conferring a drug resistance phenotype in fungal pathogens by
ABC transporters, however, little is known about these
proteins in dermatophytes--a group of fungi causing superficial
mycoses. So far only a single
ABC transporter has been extensively studied in this group of pathogens. We analyzed available genomic sequences of seven dermatophyte species in order to provide an insight into dermatophyte ABC
protein inventory. Phylogenetic studies of
ABC transporter genes and their products were conducted and included
ABC transporters of other fungi. Our results show that each dermatophyte genome studied possesses a great variety of
ABC transporter genes. Detailed analysis of selected genes and their products indicates that relatively recent duplication of
ABC transporter genes could lead to novel substrate specificity.