Posttranslational modification of Klebsiella pneumoniae flavodoxin by covalent attachment of coenzyme A, shown by sup 31 P NMR and electrospray mass spectrometry, prevents electron transfer from the nifJ protein to nitrogenase. A possible new regulatory mechanism for biological nitrogen fixation

Journal Article · Tue Feb 04 00:00:00 EST 1992 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00119a035· OSTI ID:5488769

Thorneley, R N.F.; Ashby, G A; Drummond, M H; Eady, R R; Huff, S; Macdonald, C J ^[1]; Abell, C; Schneier, A ^[2]

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1. Univ. of Sussex, Brighton (United Kingdom)
2. Univ. Chemical Lab., Cambridge (United Kingdom)

A strain of Escherichia coli (71-18) that produces ca. 15% of its soluble cytoplasmic protein as a flavodoxin, the Klebsiella pneumoniae nifF gene product, has been constructed. The flavodoxin was purified using FPLC and resolved into two forms, designated KpFldI and KpFldII, which were shown to have identical N-terminal amino acid sequences (30 residues) in agreement with that predicted by the K. pneumoniae nifF DNA sequence. {sup 31}P NMR, electrospray mass spectrometry, UV-visible spectra, and thiol group estimations showed that the single cysteine residue (position 68) of KpFldI is posttranslationally modified in KpFldII by the covalent, mixed disulfide, attachment of coenzyme A. KpFldII was inactive as an electron carrier between the K. pneumoniae nifJ product (a pyruvate-flavodoxin oxidoreductase) and K. pneumoniae nifH product (the Fe-protein of nitrogenase). This novel posttranslational modification of a flavodoxin is discussed in terms of the regulation of nitrogenase activity in vivo in response to the level of dissolved O{sub 2} and the carbon status of diazotrophic cultures.

• OSTI ID: 5488769
• Journal Information: Biochemistry; (United States), Vol. 31:4; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
COENZYMES
NUCLEAR MAGNETIC RESONANCE
FLAVINES
POST-TRANSLATION MODIFICATION
KLEBSIELLA
NITROGEN FIXATION
DEUTERIUM COMPOUNDS
ELECTRON TRANSFER
ESCHERICHIA COLI
PHOSPHORUS 31
ACRIDINES
AMINES
AROMATICS
AZAARENES
AZINES
BACTERIA
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MICROORGANISMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS ISOTOPES
PYRIDINES
RESONANCE
STABLE ISOTOPES
550201* - Biochemistry- Tracer Techniques