LmbE proteins from Bacillus cereus are de-N-acetylases with broad substrate specificity and are highly similar to proteins in Bacillus anthracis.

The genomes of Bacillus cereus and its closest relative Bacillus anthracis each contain two LmbE protein family homologs: BC1534 (BA1557) and BC3461 (BA3524). Only a few members of this family have been biochemically characterized including N-acetylglucosaminylphosphatidyl inositol (GlcNAc-PI), 1-D-myo-inosityl-2-acetamido-2-deoxy-alpha-D-glucopyranoside (GlcNAc-Ins), N,N'-diacetylchitobiose (GlcNAc(2)) and lipoglycopeptide antibiotic de-N-acetylases. All these enzymes share a common feature in that they de-N-acetylate the N-acetyl-D-glucosamine (GlcNAc) moiety of their substrates.

Directed evolution on the cold adapted properties of TAB5 alkaline phosphatase.

Psychrophilic alkaline phosphatase (AP) from the Antarctic strain TAB5 was subjected to directed evolution in order to identify the key residues steering the enzyme's cold-adapted activity and stability. A round of random mutagenesis and further recombination yielded three thermostable and six thermolabile variants of the TAB5 AP. All of the isolated variants were characterised by their residual activity after heat treatment, Michaelis-Menten kinetics, activation energy and microcalorimetric parameters of unfolding.

Exploring the role of a glycine cluster in cold adaptation of an alkaline phosphatase.

In an effort to explore the role of glycine clusters on the cold adaptation of enzymes, we designed point mutations aiming to alter the distribution of glycine residues close to the active site of the psychrophilic alkaline phosphatase from the Antarctic strain TAB5. The mutagenesis targets were residues Gly261 and Gly262. The replacement of Gly262 by Ala resulted in an inactive enzyme.