The role of tryptophan in the ferredoxin-dependent nitrite reductase of spinach.
A system has been developed for expressing a His-tagged form of the ferredoxin-dependent nitrite reductase of spinach in Escherichia coli. The catalytic and spectral properties of the His-tagged, recombinant enzyme are similar, but not identical, to those previously observed for nitrite reductase isolated directly from spinach leaf. A detailed comparison of the spectral, catalytic and fluorescence properties of nitrite reductase variants, in which each of the enzyme's eight tryptophan residues has been replaced using site-directed mutagenesis by either aromatic or non-aromatic amino acids, has been used to examine possible roles for tryptophan residues in the reduction of nitrite to ammonia catalyzed by the enzyme.
Tripathy
Jatindra N
JN
Department of Chemistry and Biochemistry, Texas Tech University, 1 Circle Drive, Lubbock, TX 79409-1061, USA.
Hirasawa
Masakazu
M
Kim
Sung-Kun
SK
Setterdahl
Aaron T
AT
Allen
James P
JP
Knaff
David B
DB
D002942:Circular Dichroism; D005288:Ferredoxins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009572:Nitrite Reductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D013053:Spectrophotometry; D018724:Spinacia oleracea / Q000201:enzymology*; D014364:Tryptophan / Q000235:genetics / Q000378:metabolism*
D005288:Ferredoxins; D014364:Tryptophan; D009572:Nitrite Reductases