Hallenbeck P L, Kaplan S
J Bacteriol. 1987 Aug;169(8):3669-78. doi: 10.1128/jb.169.8.3669-3678.1987.
A 3.4-kilobase EcoRI restriction endonuclease fragment has been cloned from the facultatively photoheterotrophic bacterium Rhodobacter sphaeroides and shown to contain the structural gene (prkA) for phosphoribulokinase (PRK) activity. The PRK activity was characterized in Escherichia coli, and the product of the reaction was identified. The prkA gene was localized to a 1,565-base-pair EcoRI-PstI restriction endonuclease fragment and gave rise to a 33-kilodalton polypeptide both in vivo and in vitro. The gene product produced in E. coli was shown to be identical to the gene product produced in R. sphaeroides. The amino acid sequence for the amino-terminal region deduced from the DNA sequence confirmed that derived for partially purified PRK derived from both E. coli and R. sphaeroides. In addition, the 3.4-kilobase EcoRI restriction endonuclease fragment coded for a 37-kilodalton polypeptide of unknown function, and preliminary evidence indicates that this DNA fragment is linked to genes coding for other activities significant in photosynthetic carbon assimilation. The genetic organization and proposed operon structure of this DNA fragment are discussed.
从兼性光能异养细菌球形红杆菌中克隆出了一个3.4千碱基的EcoRI限制性内切酶片段，该片段被证明含有磷酸核酮糖激酶（PRK）活性的结构基因（prkA）。在大肠杆菌中对PRK活性进行了表征，并鉴定了反应产物。prkA基因定位于一个1565碱基对的EcoRI - PstI限制性内切酶片段，在体内和体外均产生一条33千道尔顿的多肽。在大肠杆菌中产生的基因产物被证明与在球形红杆菌中产生的基因产物相同。从DNA序列推导的氨基末端区域的氨基酸序列证实了从大肠杆菌和球形红杆菌中部分纯化的PRK的推导序列。此外，3.4千碱基的EcoRI限制性内切酶片段编码一种功能未知的37千道尔顿多肽，初步证据表明该DNA片段与编码光合碳同化中其他重要活性的基因相连。讨论了该DNA片段的遗传组织和推测的操纵子结构。
