Primary structure of protein B from Pseudomonas putida, member of a new class of 2Fe-2S ferredoxins.
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).
Morrice
N
N
Laboratory of Protein Structure, National Institute for Medical Research, Mill Hill, London, England.
Geary
P
P
Cammack
R
R
Harris
A
A
Beg
F
F
Aitken
A
A
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D005288:Ferredoxins / Q000235:genetics*; D008969:Molecular Sequence Data; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D005288:Ferredoxins; C055693:protein B (Pseudomonas putida)