title: Molecular analysis of OsLEA4 and its contributions to improve E. coli viability.
abstract: 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 α-helical domains and without β-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 (∼29.4 kDa) was expressed after isopropylthio-β-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.
authors: Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, People's Republic of China. tzhu2002@yahoo.com.cn
authors: Tingzhang
authors: T
authors: Hu
authors: Hua
authors: H
authors: Zeng
authors: Shuai
authors: S
authors: He
authors: Yingmei
authors: Y
authors: Wu
authors: Guixue
authors: G
authors: Wang
authors: Xiaoyun
authors: X
authors: Huang
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D055874:Extreme Heat / Q000009:adverse effects; D005615:Freezing / Q000009:adverse effects; D015964:Gene Expression Regulation, Bacterial; D007544:Isopropyl Thiogalactoside; D050296:Microbial Viability / Q000235:genetics*; D012275:Oryza / Q000737:chemistry / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D020011:Protective Agents / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000502:physiology*; D054712:Salinity; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D010940:Plant Proteins; D020011:Protective Agents; D011993:Recombinant Fusion Proteins; C066246:late embryogenesis abundant protein, plant; D007544:Isopropyl Thiogalactoside