Residues in three conserved regions of the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase are required for quaternary structure

Journal Article · Wed Aug 01 00:00:00 EDT 1990 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.87.15.5768· OSTI ID:6211146

Fitchen, J H; McIntosh, L ^[1]; Knight, S; Andersson, I; Branden, C I ^[2]

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1. Michigan State Univ., East Lansing (USA)
2. Uppsala Biomedical Center (Sweden)

To explore the role of individual residues in the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase, small subunits with single amino acid substitutions in three regions of relative sequence conservation were produced by directed mutagenesis of the rbcS gene from Anabaena 7120. These altered small subunits were cosythesized with large subunits (from an expressed Anabaena rbcL gene) in Escherichia coli. Mutants were analyzed for effects on quaternary structure and catalytic activity. Changing Glu-13S (numbering used is that of the spinach enzyme) to Val, Trp-67S to Arg, Pro-73S to His, or Tyr-98S to Asn prevented accumulation of stable holoenzyme. Interpretation of these results using a model for the three-dimensional structure of the spinach enzyme based on x-ray crystallographic data suggests that our small subunit mutants containing substitutions at positions 13S and 67S probably do not assemble because of mispairing or nonpairing of charged residues on the interfacing surfaces of the large and small subunits. The failure of small subunits substituted at positions 73S or 98S to assemble correctly may result from disruption of intersubunit or intrasubunit hydrophobic pockets, respectively.

• OSTI ID: 6211146
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 87:15; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ESCHERICHIA COLI
MUTANTS
PEPTIDES
AMINO ACID SEQUENCE
RIBULOSE DIPHOSPHATE CARBOXYLASE
X-RAY DIFFRACTION
ARGININE
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
CARBON DIOXIDE
GLUTAMIC ACID
HISTIDINE
MUTAGENESIS
PROLINE
QUATERNARY COMPOUNDS
STEREOCHEMISTRY
TRYPTOPHAN
TYROSINE
AMINES
AMINO ACIDS
AMMONIUM COMPOUNDS
AROMATICS
AZAARENES
AZOLES
BACTERIA
CARBON COMPOUNDS
CARBON OXIDES
CARBON-CARBON LYASES
CARBOXY-LYASES
CARBOXYLIC ACIDS
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
ENZYMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
IMIDAZOLES
INDOLES
LABELLED COMPOUNDS
LYASES
MICROORGANISMS
MOLECULAR STRUCTURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROTEINS
PYRROLES
PYRROLIDINES
SCATTERING
550602* - Medicine- External Radiation in Diagnostics- (1980-)