Site-directed mutagenesis to determine essential residues of ribulose-bisphosphate carboxylase of Rhodospirillum rubrum Academic Article uri icon

Overview

MeSH Major

  • Arthroplasty, Replacement, Knee
  • Knee Prosthesis
  • Prosthesis-Related Infections

abstract

  • Both Lys-166 and His-291 of ribulosebisphosphate carboxylase/oxygenase from Rhodospirillum rubrum have been implicated as the active-site residue that initiates catalysis. To decide between these two candidates, we resorted to site-directed mutagenesis to replace Lys-166 and His-291 with several amino acids. All 7 of the position-166 mutants tested are severely deficient in carboxylase activity, whereas the alanine and serine mutants at position 291 are ∼40% and ∼18% as active as the native carboxylase, essentially ruling out His-291 in the Rhodospirillum rubrum carboxylase (and by inference His-298 in the spinach enzyme) as a catalytically essential residue. The ability of some of the mutant proteins to undergo carbamate formation or to bind either ribulosebisphosphate or a transition-state analogue remains largely unimpaired. This implies that Lys-166 is not required for substrate binding; rather, the results corroborate the earlier postulate that Lys-166 functions as an acid-base group in catalysis or in stabilizing a transition state in the reaction pathway. © 1987 Indian Academy of Sciences.

publication date

  • March 1987

Research

keywords

  • Academic Article

Identity

Digital Object Identifier (DOI)

  • 10.1007/BF02704670

Additional Document Info

start page

  • 203

end page

  • 214

volume

  • 11

number

  • 1-4