Molecular Analysis of OsLEA4 and Its Contributions to Improve E. coli Viability

作者：Hu, Tingzhang^*; Zeng, Hua; He, Shuai; Wu, Yingmei; Wang, Guixue; Huang, Xiaoyun

来源：Applied Biochemistry and Biotechnology, 2012, 166(1): 222-233.

DOI：10.1007/s12010-011-9418-5

• Abiotic stresses
• Late embryogenesis abundant proteins
• Oryza sativa L.
• Protein expression

OsLEA4, a late embryogenesis abundant (LEA) protein gene from rice (Oryza sativa L.), contains a 312-bp open reading frame encoding a putative polypeptide of 103 amino acids with a calculated molecular mass of 11.19 kDa and a theoretical pI of 10.04. OsLEA4 polypeptide is rich in Ala (22%), Lys (15%), Glu (9%), His (8%), Thr (8%), and Arg (7%) and lacking in Trp, Cys, Asn, and Phe residues. OsLEA4 protein contains a Pfam:LEA_1 domain architecture at positions 1-73 with three alpha-helical domains and without beta-sheet domain. In silico predictions showed that OsLEA4 protein was strongly hydrophilic with the grand average of hydropathy value of -0.816 and instability index of 27.31. The hydrophilic regions were found in the conserved motif of OsLEA4. OsLEA4 gene was introduced into Escherichia coli, and a fusion protein (similar to 29.4 kDa) was expressed after isopropylthio-beta-d-galactoside inducting by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. OsLEA4 protein enhanced the tolerance of E. coli recombinant to high salinity, heat, freezing, and UV radiation, which suggested that OsLEA4 protein may play a protective role under stressed conditions. This is the first successful use of E. coli as a prokaryotic system for LEA production from rice.

• 出版日期2012-1
• 单位重庆大学; 重庆三峡学院