ISOLATION OF STREPTOMYCES-TENDAE MUTANTS WITH AN ALTERED NIKKOMYCIN SPECTRUM
ISOLATION OF STREPTOMYCES-TENDAE MUTANTS WITH AN ALTERED NIKKOMYCIN SPECTRUM
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DOI：
10.7164/antibiotics.42.913
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发表时间：
1989-06-01
影响因子：
3.3
通讯作者：
ZAHNER, H
中科院分区：
文献类型：
--
作者：
BORMANN, C;MATTERN, S;ZAHNER, H
为了分离在尼可霉素核苷碱基4-甲酰基-4-咪唑啉-2-酮的生物合成中被阻断的Streptomyces tendae突变体，开发了检测在固体培养基上生长期间含有该碱基的尼可霉素的形成的测定。该测定基于尼可霉素的4-甲酰基咪唑酮结构与醛试剂巴比妥酸反应产生红色产物。在巴比妥酸测定中测试的18，000个N-甲基-N“-硝基-N-亚硝基胍处理的克隆中，我们分离出一个突变体，其不能形成任何含有4-甲酰咪唑酮碱基的尼可霉素（尼可霉素Cx、X和I），而是产生含有尿嘧啶的尼可霉素（尼可霉素C、Z和J）。此外，我们还分离出了具有影响2-氨基-4-羟基-4-（5-羟基-2-吡啶基）-3-甲基丁酸生物合成的突变的菌株，2-氨基-4-羟基-4-（5-羟基-2-吡啶基）-3-甲基丁酸是尼可霉素Z、X、I和I的不常见氨基酸。通过对S. tendae Tu 901/395是一株除产尼可霉素Z、X、J和I外，还产尼可霉素Kz/Kx和Oz/Ox的突变株，我们获得了仅以2-氨基-4-羟基-4-（2-吡啶基）丁酸和2-氨基-4-羟基-4-（5-羟基-2-吡啶基）丁酸为氨基酸生成尼可霉素Kz/Kx和Oz/Ox的菌株。在8-甲氧庚烯存在下，用UV 385 nm诱变该菌株（Tu 901/395-11），并选择S-2-氨乙基-L-半胱氨酸抗性克隆，导致分离出仅产生尼可霉素Kz和Kx的Tu 901/AEC 1和AEC 2。根据其尼可霉素谱，这些菌株在尼可霉素氨基酸生物合成期间在吡啶基残基处发生的羟基化步骤处被阻断。
To isolate Streptomyces tendae mutants blocked in the biosynthesis of the nikkomycin nucleoside base 4-formyl-4-imidazoline-2-one, an assay was developed to detect the formation of nikkomycins containing this base during growth on solid medium. The assay is based on the reaction of the 4-formylimidazolone structure of nikkomycins with the aldehyde reagent barbituric acid leading to red-colored products. Among 18,000 N-methyl-N''-nitro-N-nitrosoguanidine treated clones tested in the barbituric acid assay, we isolated one mutant which was incapable of forming any nikkomycins containing the 4-formylimidazolone base (nikkomycins Cx, X and I) but instead produced nikkomycins containing uracil (nikkomycins C, Z and J). In addition, we isolated strains with mutations affecting the biosynthesis of 2-amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbutyric acid, the unusual amino acid of nikkomycins Z, X, I and I. By analyzing colonies derived from single spores or protoplasts of S. tendae Tu901/395, a mutant producing besides nikkomycins Z, X, J and I, also nikkomycins Kz/Kx and Oz/Ox, we obtained strains which only formed nikkomycins Kz/Kx and Oz/Ox with 2-amino-4-hydroxy-4-(2-pyridyl)butyric acid and 2-amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-butyric acid as amino acids. Mutation of such a strain (Tu901/395-11) by UV385nm in the presence of 8-methoxypsoralen and selection of S-2-aminoethyl-L-cysteine-resistant clones led to the isolation of Tu901/AEC1 and AEC2 which produced exclusively nikkomycins Kz and Kx. According to their nikkomycin spectrum, these strains were blocked at the hydroxylation step occurring at the pyridyl residue during biosynthesis of the nikkomycin amino acid.