Kersten P J, Cullen D
Institute for Microbial and Biochemical Technology, U.S. Department of Agriculture, Madison, WI 53705.
Proc Natl Acad Sci U S A. 1993 Aug 1;90(15):7411-3. doi: 10.1073/pnas.90.15.7411.
Glyoxal oxidase is produced by ligninolytic cultures of the white-rot fungus Phanerochaete chrysosporium and is a source of the extracellular H2O2 that is required by ligninolytic peroxidases. We report here the cloning and characterization of glx-1c cDNA, which encodes glyoxal oxidase. The deduced mature protein has 537 amino acids, a molecular size of 57 kDa, and a pI of 5.1. Five potential N-glycosylation sites are present. The predicted N-terminal sequence is identical to the experimentally determined sequence of purified enzyme and is preceded by a leader peptide of 22 amino acids. The sequence of glx-1c lacks significant homology with known sequences. Specific comparisons were made between the glx-1c translated sequence and that of galactose oxidase from Dactylium dendroides because of previously observed catalytic similarities of the enzyme. Although no significant homology is observed, in both cases extensive beta-sheet regions are predicted from the primary sequences. Glyoxal oxidase activity correlates with transcript levels and is also coordinate with the lignin peroxidases in nutrient nitrogen-starved cultures.
乙二醛氧化酶由白腐真菌黄孢原毛平革菌的木质素分解培养物产生，是木质素分解过氧化物酶所需的细胞外过氧化氢的来源。我们在此报告编码乙二醛氧化酶的glx - 1c cDNA的克隆及特性。推导的成熟蛋白有537个氨基酸，分子大小为57 kDa，pI为5.1。存在五个潜在的N - 糖基化位点。预测的N端序列与纯化酶的实验测定序列相同，且前面有一个22个氨基酸的前导肽。glx - 1c的序列与已知序列缺乏显著同源性。由于先前观察到该酶的催化相似性，对glx - 1c翻译序列与来自树状指孢霉的半乳糖氧化酶的序列进行了特异性比较。尽管未观察到显著同源性，但在这两种情况下，从一级序列预测出广泛的β - 折叠区域。乙二醛氧化酶活性与转录水平相关，并且在营养氮饥饿培养物中也与木质素过氧化物酶协同。
