The dhnA gene of Escherichia coli encodes a class I fructose bisphosphate aldolase

Biochem J. 1998 Apr 15;331 ( Pt 2)(Pt 2):437-45. doi: 10.1042/bj3310437.


The gene encoding the Escherichia coli Class I fructose-1, 6-bisphosphate aldolase (FBP aldolase) has been cloned and the protein overproduced in high amounts. This gene sequence has previously been identified as encoding an E. coli dehydrin in the GenBanktrade mark database [gene dhnA; entry code U73760; Close and Choi (1996) Submission to GenBanktrade mark]. However, the purified protein overproduced from the dhnA gene shares all its properties with those known for the E. coli Class I FBP aldolase. The protein is an 8-10-mer with a native molecular mass of approx. 340 kDa, each subunit consisting of 349 amino acids. The Class I enzyme shows low sequence identity with other known FBP aldolases, both Class I and Class II (in the order of 20%), which may be reflected by some novel properties of this FBP aldolase. The active-site peptide has been isolated and the Schiff-base-forming lysine residue (Lys236) has been identified by a combination of site-directed mutagenesis, kinetics and electrospray-ionization MS. A second lysine residue (Lys238) has been implicated in substrate binding. The cloning of this gene and the high levels of overexpression obtained will facilitate future structure-function studies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Borohydrides / pharmacology
  • Chromatography, High Pressure Liquid
  • Cyanogen Bromide
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics*
  • Fructose-Bisphosphate Aldolase / chemistry*
  • Fructose-Bisphosphate Aldolase / genetics*
  • Fructose-Bisphosphate Aldolase / metabolism
  • Gene Expression
  • Lysine / analysis
  • Lysine / chemistry
  • Molecular Sequence Data
  • Molecular Weight
  • Mutagenesis, Site-Directed
  • Phylogeny
  • Polymerase Chain Reaction
  • Schiff Bases
  • Sequence Alignment
  • Sequence Analysis


  • Borohydrides
  • Schiff Bases
  • sodium borohydride
  • Fructose-Bisphosphate Aldolase
  • Lysine
  • Cyanogen Bromide