title: Polyproline II structure is critical for the enzyme protective function of soybean Em (LEA1) conserved domains.
abstract: Group 1 late embryogenesis-abundant (LEA1) proteins protect enzyme activity from dehydration and are structurally conserved with three different 20 amino acid motifs in the N-terminal, middle and C-terminal domains. Three soybean Em (LEA1) domain peptides (Em-N, Em-2M and Em-C) covering these respective motifs were constructed and had differential protective ability on lactate dehydrogenase against freeze-thaw: Em-C > Em-2M > Em-N. CD spectroscopy revealed that Em-2M and Em-C contained both polyproline II (PII) helical structure and α-helix, while Em-N had a high potential to form α-helix but did not contain PII structure. The PII helical structure between the third and fifth glycine in the middle motif was shown, through site mutation, to be critical for the enzyme protective function of soybean Em (LEA1) conserved domain under freezing stress.
authors: Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, Changchun, China.
authors: Yongdong
authors: Y
authors: Zou
authors: Ruisha
authors: R
authors: Hong
authors: Shuwen
authors: S
authors: He
authors: Guobao
authors: G
authors: Liu
authors: Zebo
authors: Z
authors: Huang
authors: Yizhi
authors: Y
authors: Zheng
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004795:Enzyme Stability; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology*; D013696:Temperature
chemical_list: D010455:Peptides; D010940:Plant Proteins; D011994:Recombinant Proteins; C066246:late embryogenesis abundant protein, plant; C011083:polyproline