Truncated hemoglobins (trHbs) constitute a familkrof small oxygen-binding heme proteins distributed in eubacteria, cyanobacteria, protozoa, and plants. Three distinct types of trHbs (HbN, HbO and HbP) have been identified within the mycobacterial genome. The soluble trHb of the cyanobacterium Nostoc commune is localized on the cytoplasmic face of the cell membrane and is expressed only under anaerobic conditions. In addition, the gene encoding trHb is coexpressed with genes of the nitrogen fixation complex. The trHb of the unicellular green alga C. eugametos is induced in response to active photosynthesis and is localized, in part, along the chloroplast thylakoid membranes. Yeast II hybridization screening was performed using TatrHb as a bait protein to elucidate putative role of TatrHb. cDNA Library for Yeast II hybridization screening was constructed with mRNA from young seedling treated 0% oxygen for 48 hours. 12 positive clones were selected by colony PCR and sequenced. Among them, 4 clones are related in photosynthesis and show highly homologe to Hordeum vulgare chloroplast photosystem I PSK-I subunit mRNA (393 bp), Zea mays photosystem II subunit PsbS1 mRNA (900 bp), Triticum aestivum ribulose-1,5-bisphosphate carboxylase/oxygenase(RubisCo) large subunit mRNA (1434 bp), Triticum aestivum ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit mRNA (525 bp).

• Dae Yeon Kim(Div. of Biotechnology, Korea University)
• Min Jeong Hong(Div. of Biotechnology, Korea University)
• Yong Weon Seo(Div. of Biotechnology, Korea University) Corresponding author