Phylogeny of fungal hemoglobins and expression analysis of the Aspergillus oryzae flavohemoglobin gene fhbA during hyphal growth.
The fhbA genes encoding putative flavohemoglobins (FHb) from Aspergillus niger and Aspergillus oryzae were isolated. Comparison of the deduced amino acid sequence of the A. niger fhbA gene and other putative filamentous fungal FHb-encoding genes to that of Ralstonia eutropha shows an overall conserved gene structure and completely conserved catalytic amino acids. Several yeasts and filamentous fungi, including both Aspergillus species have been found to contain a small FHb gene family mostly consisting of two family members. Based on these sequences the evolutionary history of the fungal FHb family was reconstructed. The isolated fhbA genes from A. oryzae and A. niger belong to a phylogenetic group, which exclusively contains Aspergillus genes. Different experimental approaches show that fhbA transcript levels appear during active hyphal growth. Moreover, in a pclA-disrupted strain with a hyperbranching growth phenotype, the transcript levels of the fhbA gene were 2–5 times higher compared to the wild-type. These results suggest that FHb from filamentous fungi have a function that is correlated to the hyphal growth phenotype.
te Biesebeke
Rob
R
Top Institute Food & Nutrition, P.O. Box 557, 6700 AN Wageningen, The Netherlands. rob.tebiesebeke@rdor.nestle.com
Levasseur
Anthony
A
Boussier
Amandine
A
Record
Eric
E
van den Hondel
Cees A M J J
CA
Punt
Peter J
PJ
D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D001236:Aspergillus oryzae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D003470:Culture Media; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D006420:Hemeproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D025301:Hyphae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D003470:Culture Media; D005656:Fungal Proteins; D006420:Hemeproteins