5.1.3.14 evolution Bacillus anthracis gneY and gneZ encode nearly identical UDP-GlcNAc 2-epimerase enzymes that catalyze the reversible conversion of UDPGlcNAc and UDP-ManNAc 748089 5.1.3.14 evolution the bacterial UDP-GlcNAc-binding site is conserved and probably unique to the nonhydrolyzing bacterial 2-epimerases. Conservation of the allosteric site residues in the nonhydrolyzing bacterial 2-epimerases indicates that the allosteric regulatory mechanism, which involves direct interaction between one substrate molecule in the active site and another in the allosteric site, is used exclusively by this class of bacterial enzymes 726555 5.1.3.14 malfunction deletions of early wall teichoic acid (WTA) biosynthetic enzymes are nonlethal, but cause diverse attenuated virulence phenotypes, deletions of later steps in WTA biosynthesis are not generally tolerated and the enzymes are normally essential for growth, an essential gene paradox. The beta-lactam antibiotic imipenem exhibits restored bactericidal activity against mnaA mutants in vitro and concomitant efficacy against 2-epimerase defective strains in a mouse thigh model of MRSA infection. Complementing DELTAcap5P mnaASa P12L and DELTAcap5P mnaASa Y194* with either cap5P or mnaASa reintroduced on an inducible plasmid restores WTA polymer levels, resistance to each of the beta-lactams tested, and wild-type sensitivity to L638 -, 755205 5.1.3.14 malfunction deletions of early wall teichoic acid (WTA) biosynthetic enzymes are nonlethal, but cause diverse attenuated virulence phenotypes, deletions of later steps in WTA biosynthesis are not generally tolerated and the enzymes are normally essential for growth, an essential gene paradox. The beta-lactam antibiotic imipenem exhibits restored bactericidal activity against mnaA mutants in vitro and concomitant efficacy against 2-epimerase defective strains in a mouse thigh model of MRSE infection -, 755205 5.1.3.14 malfunction enzyme deficiency causes the disease sialuria in humans. Hereditary inclusion body myopathy, h-IBM, is also a disease caused by different mutations in the GNE gene, it is an autosomal recessive neuromuscular disorder characterized by adult onset, slowly progressive skeletal muscle weakness, and typical histological features as rimmed vacuoles and filamentous inclusions. Sialuria is caused by the loss of feedback control of UDP-GlcNAc 2-epimerase activity due to the mutation of only one of the two arginine residues 263 and 266. Sialuria leads to massive production of free Neu5Ac, which accumulates in the cytoplasm and results in mental retardation and hepatomegaly 702507 5.1.3.14 malfunction GNE deficiency can lead to hereditary inclusion body myopathy, HIBM, phenotypes, overview 703285 5.1.3.14 malfunction GNE mutations can result in two human disorders, hereditary inclusion body myopathy, HIBM, and sialuria 703912 5.1.3.14 malfunction inactivation of GNE causes early embryonic lethality 703905 5.1.3.14 malfunction mutation of this enzyme causes changes in cell morphology and the thermoresistance of the cell wall -, 749249 5.1.3.14 malfunction mutations in the GNE gene are associated with autosomal recessive hereditary inclusion body myopathy, i.e. HIBM or IBM2, a progressive adult onset muscle wasting disorder characterized by sparing of the quadriceps. IBM2 is also known as distal myopathy with rimmed vacuoles or nonaka myopathy 703865