Molecular analysis of the hydrogenosomal ferredoxin of the anaerobic protist Trichomonas vaginalis.
We have determined the primary structure of the [2Fe-2S]ferredoxin of the anaerobic protist Trichomonas vaginalis. This protein, situated in the hydrogenosome, is composed of 93 amino acids. A comparison of T. vaginalis ferredoxin with greater than 80 other ferredoxins shows the closest similarity to [2Fe-2S]putidaredoxin of the aerobic bacterium Pseudomonas putida and a lesser one to mitochondrial [2Fe-2S]ferredoxins of vertebrates. This similarity is reflected in the overall primary structure and in the spacing of cysteine residues coordinating the iron-sulfur center. The primary structure, but not the environment of the iron-sulfur center, also shows similarity with [2Fe-2S]ferredoxins of photosynthetic organisms and halobacteria. We have cloned and analyzed the T. vaginalis ferredoxin gene. The gene is present in a single copy and devoid of introns. It gives rise to a transcript with unusually short 5' and 3' untranslated regions of 16 and 18 nucleotides, respectively. DNA sequence analysis of the gene predicts an additional 8 amino acids at the amino terminus which are absent from the purified protein. This amino-terminal region of the protein is characterized by properties typical of mitochondrial presequences.
Department of Microbiology and Immunology, University of California School of Medicine, Los Angeles 90024.
P J
PJ
Johnson
C E
CE
d'Oliveira
T E
TE
Gorrell
M
M
Müller
D000595:Amino Acid Sequence; D000693:Anaerobiosis; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005288:Ferredoxins / Q000235:genetics* / Q000378:metabolism; D015723:Gene Library; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014246:Trichomonas vaginalis / Q000235:genetics* / Q000378:metabolism
D005288:Ferredoxins; D012313:RNA; D004247:DNA