Pease E A, Andrawis A, Tien M
Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.
J Biol Chem. 1989 Aug 15;264(23):13531-5.
A cDNA clone encoding a manganese-dependent peroxidase from the filamentous fungus Phanerochaete chrysosporium was isolated and characterized. The clone, lambda MP-1, was isolated by screening a lambda gt11 expression library with polyclonal antibodies raised against a purified manganese-dependent peroxidase (isozyme H4, pI 4.5). The lambda MP-1 cDNA sequence predicts a mature protein containing 358 amino acids with a molecular weight of 37,711 preceded by a leader peptide of 24 amino acid residues. The N-terminal amino acid sequence of a purified manganese-dependent peroxidase (H4) corresponds to the sequence deduced from the cDNA. Some homology (58% in nucleotide sequence and 65% in amino acid sequence) is observed between the manganese-dependent peroxidase and lignin peroxidase isozyme H8. The highest degree of similarity is observed near the enzyme active site. Residues essential for peroxidase activity, the distal and proximal histidines, can be identified in the amino acid sequence. Near these residues, homology is also observed with several other peroxidases. Northern blot analysis of poly(A)+ RNA from nitrogen-limited P. chrysosporium cultures indicates that the level of messenger RNA correlates with expression of the enzyme and its activity. This is consistent with the regulation of the enzyme being at the level of transcription.
从丝状真菌黄孢原毛平革菌中分离并鉴定了一个编码锰依赖过氧化物酶的cDNA克隆。该克隆λMP-1是通过用针对纯化的锰依赖过氧化物酶（同工酶H4，pI 4.5）产生的多克隆抗体筛选λgt11表达文库而分离得到的。λMP-1 cDNA序列预测一个成熟蛋白含有358个氨基酸，分子量为37711，其前面有一个24个氨基酸残基的前导肽。纯化的锰依赖过氧化物酶（H4）的N端氨基酸序列与从cDNA推导的序列一致。在锰依赖过氧化物酶和木质素过氧化物酶同工酶H8之间观察到一些同源性（核苷酸序列中为58%，氨基酸序列中为65%）。在酶活性位点附近观察到最高程度的相似性。在氨基酸序列中可以鉴定出过氧化物酶活性所必需的残基，即远端和近端组氨酸。在这些残基附近，还观察到与其他几种过氧化物酶的同源性。对来自氮限制的黄孢原毛平革菌培养物的聚腺苷酸加尾RNA进行Northern印迹分析表明，信使RNA的水平与该酶的表达及其活性相关。这与该酶在转录水平上的调控是一致的。
