LEA蛋白质11-氨基酸基序与植物抗旱性

11-amino acid motif in late embryogenesis abundant protein (LEA) and plant desiccation tolerance

分析了8种重要农作物第三组LEA蛋白质序列中的94个11-氨基酸基序.得出一致性序列为TAEAAKQKAGE.LEA3蛋白质中11-氨基酸基序呈多拷贝串联排列,其长度占蛋白质序列总长度的40%～60%.带电荷/极性氨基酸和疏水氨基酸数目分别占重复序列氨基酸总数的70.89%和29.11%.11-氨基酸基序的二级结构多呈α-螺旋结构.其中第1,2,4,5,9位疏水氨基酸形成螺旋蛋白质分子的疏水界面,其余位置的氨基酸形成螺旋分子的亲水界面.LEA3蛋白质全序列平均亲水指数为-0.95～-1.22.无信号肽序列.8种LEA3蛋白分子的上述特性与植物的抗旱性有关.

There is TAEAAKQKAGE of the consensus sequences in eight kinds of LEA 3 proteins of the crops obtained from nr database in NCBI.Arranging tandemly,the 11-mer motif with several repeats are about 40%～60% in length in their in the full sequences of LEA 3 proteins.The number of charged/polar and apolar residues is 70.89% and 29.11% in the repeat sequences,respectively.The secondary structure of 11-mer motifs is almost α-helix molecules.Apolar residues in the position of 1,2,4,5,9 are formed with the hydrophobic faces in the helices and the rest of charged/polar residues are formed with the hydrophilic faces.Hydrophilic index of eight LEA 3 sequences could be -0.95 to -1.22.These LEA 3 proteins have no signal peptides at N terminal ends.It is speculated that these chemical characters of LEA 3 protein contribute to desiccation-tolerance of plants.