Poster Presentation The 45th Lorne Conference on Protein Structure and Function 2020

Identification and structural prediction of the native protease of a newly isolated yeast specie from spoilt orange (#313)

Okojie Eseoghene Lorrine 1 2 3 , Raja Noor Zaliha Raja Abd. Rahman 1 2 3 , Tan Joo Shun 4 , Abu Bakar Salleh 3 , Siti Nurbaya Oslan 1 2 3
  1. Department of Biochemistry , Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia,43400 Serdang., Serdang, Selangor, Malaysia
  2. Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Serdang, Selangor, Malaysia
  3. Enzyme and Microbial Technology Research Centre,, Universiti Putra Malaysia, 43400, Selangor, Serdang, Malaysia
  4. School of Industrial Technology, Universiti Sains Malaysia, 11800 , Pulau, Pinang, Malaysia

Proteolytic activity of native proteases is a naturally occurring phenomenon within all living cells. Pichia sp. Strain SO which was isolated from spoilt orange has been used as a host for recombinant protein expression. However, the proteolytic activity of the native protease has deterred the overexpression of the recombinant protein. This study aims to identify the native protease of strain SO and predict its structure. Protease activity assayed using azocasein as substrate showed activities of more than 200U/ml. Then a sophisticated bioinformatics tools BLAST and Hidden Markov Model (HMM) were implemented to search for the possible protease(s) in strain SO proteome (5229 proteins). Aspartyl protease of strain SO with 97.55% similarity to Meyerozyma sp.JA9 was identified. Using Phyre2 prediction software, aspartyl protease structurally possessed 100% confidence score with 89% coverage to PDB ID d1miqa. D112 and D297 were predicted to be the conserved catalytic residues of this protease. In conclusion, an aspartyl protease of strain SO was successfully identified and structurally predicted. Hence, it can be used as the target to develop a protease-deficient yeast strain as a host for improved recombinant protein expression.