Morrice N, Geary P, Cammack R, Harris A, Beg F, Aitken A
Laboratory of Protein Structure, National Institute for Medical Research, Mill Hill, London, England.
FEBS Lett. 1988 Apr 25;231(2):336-40. doi: 10.1016/0014-5793(88)80845-7.
The primary structure of the 2Fe-2S ferredoxin (protein B) from the benzene dioxygenase system of Pseudomonas putida strain NCIB 12190 was determined by gas-phase sequencing of the protein and its fragments. Fast atom bombardment mass spectrometry indicated a molecular mass of 11,860 Da. The sequence contained five cysteine residues, four of which would be required to coordinate the iron-sulphur cluster. The amino acid sequence determined in the present study is compared to that of a protein deduced from the DNA sequence from another strain of Pseudomonas putida. Little sequence homology was observed when protein B was compared to 2Fe-2S ferredoxins from plant and cyanobacterial sources. The novel sequence determined here suggests a new class of ferredoxin, which is consistent with the observed mid-point redox potential being significantly less negative (-155 mV) than those of the 2Fe-2S ferredoxins involved in photosynthesis (-310 to -455 mV).
通过对恶臭假单胞菌NCIB 12190苯双加氧酶系统中的2Fe-2S铁氧化还原蛋白（蛋白质B）及其片段进行气相测序，确定了其一级结构。快原子轰击质谱分析表明其分子量为11,860道尔顿。该序列包含五个半胱氨酸残基，其中四个是配位铁硫簇所必需的。将本研究中确定的氨基酸序列与从另一株恶臭假单胞菌的DNA序列推导的蛋白质序列进行了比较。当将蛋白质B与来自植物和蓝细菌来源的2Fe-2S铁氧化还原蛋白进行比较时，观察到的序列同源性较低。此处确定的新序列表明存在一类新的铁氧化还原蛋白，这与观察到的中点氧化还原电位（-155 mV）明显低于参与光合作用的2Fe-2S铁氧化还原蛋白的中点氧化还原电位（-310至-455 mV）是一致的。
