A PROKARYOTIC REGULATORY FACTOR WITH A HISTONE H1-LIKE CARBOXY-TERMINAL DOMAIN - CLONAL VARIATION OF REPEATS WITHIN ALGP, A GENE INVOLVED IN REGULATION OF MUCOIDY IN PSEUDOMONAS-AERUGINOSA
A PROKARYOTIC REGULATORY FACTOR WITH A HISTONE H1-LIKE CARBOXY-TERMINAL DOMAIN - CLONAL VARIATION OF REPEATS WITHIN ALGP, A GENE INVOLVED IN REGULATION OF MUCOIDY IN PSEUDOMONAS-AERUGINOSA
复制标题
DOI：
10.1128/jb.172.10.5544-5554.1990
复制
发表时间：
1990-10-01
影响因子：
3.2
通讯作者：
KONYECSNI, WM
中科院分区：
文献类型：
--
作者：
DERETIC, V;KONYECSNI, WM
在铜绿假单胞菌中发现了一种新的原核转录调控元件AlgP，具有组蛋白H1样羧基端结构域。AlgP是关键生物合成基因algD转录所必需的，algD是产生导致铜绿假单胞菌粘体的胞外多糖藻酸盐所必需的。粘液性是铜绿假单胞菌的关键毒力决定因子，其总是与导致囊性纤维化的高死亡率的呼吸道感染相关。在这里，我们表明，AlgP和组蛋白H1都有重复单位的Lys-Pro-Ala-Ala基序（KPAA）和它的变化在其长（超过100个氨基酸）的羧基末端结构域。组蛋白H1尾部的这一区域已被证明与真核染色质纤维中的接头DNA结合。一个合成的50-mer肽组成的重复从AlgP羧基末端结构域被发现结合DNA的迁移率变化的DNA结合试验。AlgP由一个基因编码，该基因含有多个直接重复序列，这些重复序列被组织为串联的、头到尾的、12个碱基对（bp）的单元，与6个高度保守的75个bp的单元重叠。algP基因的重复结构似乎参与了铜绿假单胞菌中粘液性亚稳特征的过程。相对较大的DNA重排跨越该地区的串联直接重复编码的羧基末端组蛋白H1样结构的AlgP被检测到在几个菌株后，从类粘蛋白的nonmucoid表型转换。可检测到的algP重排与过渡到非粘液状态的频率从应变应变变化，范围从0到50%。具有algP的明显重排的染色体拷贝的非粘液样衍生物用含有来自铜绿假单胞菌PAO的algP的质粒补充到粘液性。当一个随机收集的粘液样菌株，分离自不同的囊性纤维化患者，通过聚合酶链反应进行了分析，algP的应变依赖性序列变异的额外水平进行了观察。发现12-bp重复序列的数量变化;然而，它们似乎并不影响所检查菌株的粘液状态。因此，algP的重复区域似乎是DNA重排和菌株依赖性变异的热点。
A novel procaryotic transcriptional regulatory element, AlgP, with a histone H1-like carboxy-terminal domain was identified in Pseudomonas aeruginosa. AlgP is required for transcription of the key biosynthetic gene algD, which is necessary for production of the exopolysaccharide alginate causing mucoidy in P. aeruginosa. Mucoidy is a critical virulence determinant of P. aeruginosa invariably associated with the respiratory infections causing high mortality in cystic fibrosis. Here we show that AlgP and histones H1 both have repeated units of the Lys-Pro-Ala-Ala motif (KPAA) and its variations within their long (over 100 amino acids) carboxy-terminal domains. This region of histone H1 tails has been shown to bind to the linker DNA in eucaryotic chromatin fibers. A synthetic 50-mer peptide consisting of repeats from the AlgP carboxy-terminal domain was found to bind DNA in a mobility shift DNA-binding assay. AlgP is encoded by a gene that contains multiple direct repeats organized as tandem, head-to-tail, 12-base-pair (bp) units overlapping with six highly conserved 75-bp units. The repetitive structure of the algP gene appears to participate in the processes underlying the metastable character of mucoidy in P. aeruginosa. Relatively large DNA rearrangements spanning the region with tandem direct repeats encoding the carboxy-terminal histone H1-like structure of AlgP were detected in several strains upon conversion from the mucoid to the nonmucoid phenotype. The frequency of the detectable algP rearrangements associated with the transition into the nonmucoid state varied from strain to strain and ranged from 0 to 50%. The nonmucoid derivatives with the clearly rearranged chromosomal copy of algP were complemented to mucoidy with plasmids containing algP from P. aeruginosa PAO. When a random collection of mucoid strains, isolated from different cystic fibrosis patients, was analyzed by using polymerase chain reaction, an additional level of strain-dependent sequence variation in algP was observed. Variations in the number of the 12-bp repeats were found; however, they did not appear to influence the mucoid status of the strains examined. Thus, the repeated region of algP appears to be a hot spot for DNA rearrangements and strain-dependent variability.