Abstract
High-affinity nitrite influx into mycelia of Aspergillus nidulans has been characterized by use of (13)NO(2)(-), giving average K(m) and V(max) values of 48 ± 8 μM and 228 ± 49 nmol mg(-1) dry weight (DW) h(-1), respectively. Kinetic analysis of a plot that included an additional large number of low-concentration fluxes gave an excellent monophasic fit (r(2) = 0.96), with no indication of sigmoidal kinetics. Two-dimensional (2D) and three-dimensional (3D) models of AnNitA are presented, and the possible roles of conserved asparagine residues N122 (transmembrane domain 3 ]Tm 3]), N173 (Tm 4), N214 (Tm 5), and N246 (Tm 6) are discussed.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Amino Acid Substitution
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Aspergillus nidulans / growth & development
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Aspergillus nidulans / metabolism*
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Cell Membrane / metabolism
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Conserved Sequence
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Fungal Proteins / genetics
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Fungal Proteins / isolation & purification
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Fungal Proteins / metabolism*
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Kinetics
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Membrane Transport Proteins / genetics
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Membrane Transport Proteins / isolation & purification
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Membrane Transport Proteins / metabolism*
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Models, Molecular
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Nitrites / metabolism*
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Protein Structure, Secondary
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Protein Structure, Tertiary
Substances
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Fungal Proteins
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Membrane Transport Proteins
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Nitrites