Structure and Function of a Novel Cold Regulated Cold Shock Domain Containing Protein from an Obligate Psychrophilic Yeast, Glaciozyma antarctica

• Main Authors: Jennifer Charles, Makdi Masnoddin, Farhan Nazaie, Nur Athirah Yusof
• Format: Article
• Language: English
• Published: 2020
• Subjects: Q Science (General)
• Online Access: https://eprints.ums.edu.my/id/eprint/25962/1/Structure%20and%20Function%20of%20a%20Novel%20Cold%20Regulated%20Cold%20Shock%20Domain%20Containing%20Protein%20from%20an%20Obligate%20Psychrophilic%20Yeast%2C%20Glaciozyma%20antarctica.pdf; https://eprints.ums.edu.my/id/eprint/25962/

Cold shock domain (CSD)-containing proteins are one of the groups of the evolutionarily conserved nucleic acid-binding proteins in all three domains of life consisting of an ancient beta-barrel fold that serves to bind nucleic acids. The cDNA of a novel protein-coding gene containing CSD was cloned from Glaciozyma antarctica designated as Ga16676. The full length of Ga16676 gene with the size of 1335 bp encodes for an N-terminal CSD with conserved nucleic acids binding motif RNP1 and RNP2. The Ga16676 gene was cloned in pET30 Ek/LIC, sequenced, expressed and its resistance towards cold was characterized. Protein expression of recombinant Ga16676 showed overexpressed soluble expression in both supernatant and pellet forms at 20°C. The effects of CSD protein overexpression on colony formation shows that E. coli cells were able to grow at 37°C and 20°C but not at 4°C while E. coli_Ga16676 cells were able to grow at all temperatures tested. In addition, E. coli_Ga16676 cells showed higher growth rate compared to empty E. coli cells at 10°C. Structural analysis of Ga16676 reveals some interesting findings such as more aromatic interactions for efficient binding in low energy environment, a longer loop that may contribute to structural flexibility and clustering of charged amino acids on the protein surface that is important for protein stability and flexibility.