Affiliations: Department of Chemistry and Biochemistry, University
of Northern Iowa, Cedar Falls, Iowa 50614, USA | Department of Biology, Wartburg College, Waverly, Iowa
50677, US | Mathematics and Science Department, Hawkeye Community
College, Waterloo, Iowa 50704, USA
Abstract: An in silico approach was used to investigate cytochrome c and
the cytochrome c gene of Phanerochaete chrysosporium. The cytochrome c
gene contains four introns. Omission of the introns reveals a DNA sequence
coding for a complete predicted amino acid sequence for P. chrysosporium
cytochrome c consistent with those of other cytochromes c. Fungal cytochromes c
often have a short N-terminal peptide preceding a Gly that is the N-terminal
amino acid in many cytochromes c. Thus a microexon codes for an N-terminal
pentapeptide (MetProTyrAlaPro) in P. chrysosporium that is identical to
the N-terminal pentapeptide of Schizosaccharomyces pombe, a well studied
yeast, the genome of which bears more similarity to higher eukaryotes than to
other fungi. The fourth intron, when omitted, reveals the presence of another
microexon resulting in a sequence for the C-terminal portion of the protein and
the stop codon. Interestingly, two interpretations for the sequence of this
intron leads to predictions that the C-terminal sequence ends with either
AlaValAsn or AlaTyr. Selected aspects of the molecular architecture of
cytochrome c and regulatory control elements of the P. chrysosporium
cytochrome c gene were analyzed and compared to those present in other fungi
and to those present in genes for lignin peroxidases and cytochromes P-450, two
important families of hemeproteins produced by this fungus.
