Cloning and characterization of trehalose-6-phosphate synthase gene from Rhizopus oryzae


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2009

Öğrenci: GÜLSÜM EBRU ÖZER UYAR

Danışman: HALUK HAMAMCI

Özet:

In many organisms, trehalose protects against several environmental stresses, such as heat, desiccation and salt, probably by stabilizing protein structures and lipid membranes. Trehalose-6-phosphate synthase 1 (TPS1) is a subunit of trehalose synthase complex in fungi; it plays a key role in the biosynthesis of trehalose. In this study, a TPS1 gene fragment in R. oryzae was cloned successfully by PCR with primers designed according to eight hypothetical proteins found from BLAST search which was performed by using S. cerevisiae TPS1 gene template. The full length of R. oryzae TPS1 gene (designated RoTPS1) was attained by RTPCR with primers specific to the 3′ and 5′end of the RoTPS1 cDNA. The RoTPS1cDNA was composed of 2505 bps encoding a protein of 834 amino acids with a molecular mass of 93.8 kDa. The amino acid sequence has relatively high homology with the TPS1s of several other organisms. RoTPS1 was further characterized by transformation into S. cerevisiae tps1 mutant. In galactose media, the growth curves of wild type, tps1 mutant and transformant S. cerevisiae cells had a comparable pattern in general, tps1 mutant reached to a higher maximum cell concentration compared to the others and wild type had a slightly lower specific growth rate compared to the tps1 mutant and transformed cells. Trehalose levels of transformant and wild type cells were increased up to 37 mg/gdw in the stationary phase.