The novel extracellular Streptomyces reticuli haem-binding protein HbpS influences the production of the catalase-peroxidase CpeB.
The novel extracellular Streptomyces reticuli haem-binding protein HbpS influences the production of the catalase-peroxidase CpeB.
复制标题
新型胞外网状链霉菌血红素结合蛋白 HbpS 影响过氧化氢酶-过氧化物酶 CpeB 的产生。
作者：
D. Ortiz de Orué Lucana;Tanja Schaa;H. Schrempf
革兰氏阳性土壤细菌和纤维素降解菌Streptomyces reticuli合成菌丝体相关酶CpeB，其显示血红素依赖性过氧化氢酶和过氧化物酶活性，以及血红素非依赖性锰过氧化物酶活性。在cpeB基因的下游，鉴定了一个迄今未知的基因。在大肠杆菌、变铅青链霉菌和原链霉菌染色体内的基因破坏突变体中克隆了新基因及其突变衍生物。通过构建牛心虫宿主，比较生理学、生物化学和免疫学研究，推断出新基因产物的以下特征。(i)该蛋白质被发现在细胞外;信号肽内的双胞苷取代废除了其分泌。(ii)高度纯化的蛋白质与血红素特异性相互作用，因此被命名为HbpS（链霉菌血红素结合蛋白）。(iii)HbpS含有三个被疏水氨基酸包围的组氨酸残基;其中一个位于基序LX（3）THLX（10）AA内，其与酵母细胞色素c过氧化物酶LX（2）THLX（10）AA内的基序相关，所述基序的组氨酸残基与血红素相互作用。(iv)向链霉菌培养物中加入血红素（血红素的Fe（3+）氧化形式）导致HbpS水平提高，这与血红素抗性增加相关。(v)HbpS的存在增加了含血红素的高活性过氧化氢酶-过氧化物酶CpeB的合成。在这个过程中，HbpS可以作为一个伴侣，结合血红素，然后将其提供给菌丝体相关的CpeB; HbpS也可以与膜相关的蛋白质参与的信号转导级联调节CpeB的表达。(vi)HbpS与迄今未知功能的细菌蛋白质共享不同程度的氨基酸同一性。本报告有助于阐明这些蛋白质的生物学功能。
The Gram-positive soil bacterium and cellulose degrader Streptomyces reticuli synthesizes the mycelium-associated enzyme CpeB, which displays haem-dependent catalase and peroxidase activity, as well as haem-independent manganese-peroxidase activity. Downstream of the cpeB gene, a so far unknown gene was identified. The new gene and its mutated derivatives were cloned in Escherichia coli as well as in Streptomyces lividans and a gene-disruption mutant within the chromosome of the original S. reticuli host was constructed, comparative physiological, biochemical and immunological studies then allowed the deduction of the following characteristics of the novel gene product. (i) The protein was found extracellularly; the substitution of twin arginines within the signal peptide abolished its secretion. (ii) The highly purified protein interacted specifically with haem and hence was designated HbpS (haem-binding protein of Streptomyces). (iii) HbpS contained three histidine residues surrounded by hydrophobic amino acids; one of them was located within the motif LX(3)THLX(10)AA, which is related to the motif within the yeast cytochrome c peroxidase LX(2)THLX(10)AA whose histidine residue interacts with haem. (iv) The addition of haemin (Fe(3+) oxidized form of haem) to the Streptomyces cultures led to enhanced levels of HbpS which correlated with increased haemin-resistance. (v) The presence of HbpS increased synthesis of the highly active catalase-peroxidase CpeB containing haem. In this process HbpS could act as a chaperone that binds haem and then delivers it to the mycelium-associated CpeB; HbpS could also interact with membrane-associated proteins involved in a signal transduction cascade regulating the expression of cpeB. (vi) HbpS shared varying degrees of amino acid identities with bacterial proteins of so far unknown function. This report contributes to the elucidation of the biological function of these proteins.
血红素在细胞色素 c6 生物合成中的作用。
DOI：
--
发表时间：
1994
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Howe,G;Merchant,S
通讯作者：
Merchant,S
影响因子：
2.9
作者：
BLAKE, MS;JOHNSTON, KH;GOTSCHLICH, EC
通讯作者：
GOTSCHLICH, EC