Khosla C, Bailey J E
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125.
Mol Gen Genet. 1988 Sep;214(1):158-61. doi: 10.1007/BF00340195.
Vitreoscilla hemoglobin is involved in oxygen metabolism of this bacterium, possibly in an unusual role for a microbe. We have isolated the Vitreoscilla hemoglobin structural gene from a pUC19 genomic library using mixed oligodeoxy-nucleotide probes based on the reported amino acid sequence of the protein. The gene is expressed in Escherichia coli from its natural promoter as a major cellular protein. The nucleotide sequence, which is in complete agreement with the known amino acid sequence of the protein, suggests the existence of promoter and ribosome binding sites with a high degree of homology to consensus E. coli upstream sequences. In the case of at least some amino acids, a codon usage bias can be detected which is different from the biased codon usage pattern in E. coli. The downstream sequence exhibits homology with the 3' end sequences of several plant leghemoglobin genes. E. coli cells expressing the gene contain greater than fivefold more heme than controls.
透明颤菌血红蛋白参与了这种细菌的氧代谢，这可能对微生物来说是一种不同寻常的作用。我们基于已报道的该蛋白氨基酸序列，使用混合寡脱氧核苷酸探针从pUC19基因组文库中分离出了透明颤菌血红蛋白结构基因。该基因在大肠杆菌中从其天然启动子开始表达，成为一种主要的细胞蛋白。核苷酸序列与该蛋白已知的氨基酸序列完全一致，表明存在与大肠杆菌上游共有序列具有高度同源性的启动子和核糖体结合位点。在至少一些氨基酸的情况下，可以检测到密码子使用偏好，这与大肠杆菌中的偏好密码子使用模式不同。下游序列与几种植物豆血红蛋白基因的3'端序列具有同源性。表达该基因的大肠杆菌细胞所含的血红素比对照细胞多五倍以上。
