Abstract
Background and Objectives:Structure of a eukariotic gene consists of different parts at upstream and downstream regions of genes. These parts include promotor, special motifes before start codon, start codone, exprerssion regulatory sequences, conserved sequences during evolutionary, intron(s), exon and their especial elements and finaly the sign of poly A tail.
Materials and Methods: During this study using degenerate PCR and Inverse PCR (IPCR) search for detection and sequencing of plb2 gene from A. fumigatus was carried out. Then, the arrengement of gene structure elements was considered in this gene.
Results: Analysis of plb2 gene showed specific sequences on upstream and downstream regions of the gene. At the upstream part of the gene there are three TATA box or TATA resembling sequence in -71 – 252 positions of +1 nucleotide, two CAAT motifes in -124 and -227bp positions, two CAAC motifes in -146 and 306bp position from +1 nucleotide and an unusual GTG start codon after three nucleotide of the last CT (pyrimidine) rich region. Also several CT rich areas, one 59bp intron with the usual TACTCAC internal nucleotide, six GATA effective motifes as expression inhibitor under nitogen influence (AREA) at the upstream region and a GTGGGG sequence as effettive motife for expression inhibitor under the influence of cabon (CREA) were investigated. Gene regulator sequences under the effect of pH (PACC) was not detected in this gene.
Conclusion: Analysis of plb2 gene showed typical characters of a eukariotic gene structure including TATA box, CAAT, CAAC and CT rich sequences at the expected distance from +1 nucleotide. Also, sequenced gene had an unusual GTG start codone, one intron like introns of phospholipase genes in other fungi, gene expression regulator sequences under nitrogen and carbon influence but not gene regulator sequences under effect of pH.