Zhou J, Rumeau D, Showalter A M
Department of Botany, Ohio University, Athens 45701.
Plant Mol Biol. 1992 Oct;20(1):5-17. doi: 10.1007/BF00029144.
Extensins comprise a family of structural cell wall hydroxyproline-rich glycoproteins in plants. Two tomato genomic clones, Tom J-10 and Tom L-4, were isolated from a tomato genomic DNA library by in situ plaque hybridization with extensin DNA probes. Tom J-10 encoded an extensin with 388 amino acid residues and a predicted molecular mass of 43 kDa. The Tom J-10 encoded extensin lacked a typical signal peptide sequence, but contained two distinct protein domains consisting of 19 tandem repeats of Ser-Pro4-Ser-Pro-Lys-Tyr-Val-Tyr-Lys at the amino terminus which were directly followed by 8 tandem repeats of the consensus sequence Ser-Pro4-Tyr3-Lys-Ser-Pro4-Ser-Pro at the carboxy terminus. RNA blot hybridization analysis with the Tom J-10 extensin probe demonstrated the presence of a 4.0 kb tomato stem mRNA which accumulated markedly in response to wounding. Tom L-4 encoded an extensin with 322 amino acid residues and a predicted molecular mass of 35 kDa. The Tom L-4 encoded extensin contained a typical signal peptide sequence at the amino terminus and was followed by at least 3 distinct domains. These domains consisted of an amino terminal domain containing several Lys-Pro and Ser-Pro4 repeat units, a central domain with repeats of the consensus sequence Ser-Pro2-5-Thr-Pro-Ser-Tyr-Glu-His-Pro-Lys-Thr-Pro, and a carboxy terminal domain containing repeats of the consensus sequence Ser-Ser-Pro4-Ser-Pro-Ser-Pro4-Thr-Tyr1-3. RNA blot hybridization analysis with the Tom L-4 extensin probe demonstrated the presence of a 2.6 kb tomato stem mRNA which accumulated in response to wounding.
伸展蛋白是植物中一类富含羟脯氨酸的细胞壁结构糖蛋白家族。通过用伸展蛋白DNA探针进行原位噬菌斑杂交，从番茄基因组DNA文库中分离出两个番茄基因组克隆，Tom J - 10和Tom L - 4。Tom J - 10编码一种含有388个氨基酸残基、预测分子量为43 kDa的伸展蛋白。Tom J - 10编码的伸展蛋白缺乏典型的信号肽序列，但在氨基末端包含两个不同的蛋白质结构域，由19个Ser - Pro4 - Ser - Pro - Lys - Tyr - Val - Tyr - Lys串联重复组成，紧接着在羧基末端是8个共有序列Ser - Pro4 - Tyr3 - Lys - Ser - Pro4 - Ser - Pro的串联重复。用Tom J - 10伸展蛋白探针进行RNA印迹杂交分析表明，存在一种4.0 kb的番茄茎mRNA，其在受伤时显著积累。Tom L - 4编码一种含有322个氨基酸残基、预测分子量为35 kDa的伸展蛋白。Tom L - 4编码的伸展蛋白在氨基末端含有典型的信号肽序列，后面跟着至少3个不同的结构域。这些结构域包括含有几个Lys - Pro和Ser - Pro4重复单元的氨基末端结构域、具有共有序列Ser - Pro2 - 5 - Thr - Pro - Ser - Tyr - Glu - His - Pro - Lys - Thr - Pro重复的中央结构域，以及含有共有序列Ser - Ser - Pro4 - Ser - Pro - Ser - Pro4 - Thr - Tyr1 - 3重复的羧基末端结构域。用Tom L - 4伸展蛋白探针进行RNA印迹杂交分析表明，存在一种2.6 kb的番茄茎mRNA，其在受伤时积累。
