title: Allosteric regulation of glucosamine-6-phosphate deaminase (NagB) and growth of Escherichia coli on glucosamine.
abstract: Growth on N-acetylglucosamine (GlcNAc) produces intracellular N-acetylglucosamine-6-phosphate (GlcNAc6P), which affects the regulation of the catabolism of amino sugars in Escherichia coli in two ways. First, GlcNAc6P is the inducing signal for the NagC repressor, and thus it increases the expression of the enzymes of the nagE-nagBACD operon. Second, it is the allosteric activator of glucosamine-6P (GlcN6P) deaminase, NagB, and thus increases the catalytic capacity of this key enzyme in the metabolism of amino sugars. We showed previously that both the level of expression of the nagB gene and the transport of glucosamine were limiting the growth rate on GlcN (L. I. Alvarez-Añorve et al., J. Bacteriol. 187:2974-2982, 2005). We were unable to conclude if the lack of allosteric activation of wild-type NagB was also contributing to the slower growth rate on GlcN. Using a single-copy plasmid, with a constitutive promoter, we have separated the effects of GlcNAc6P on the NagB protein level and on deaminase activity. We show that over a range of intracellular NagB concentrations it is the quantity of the substrate, GlcN6P, which is limiting growth rather than the concentration of the allosteric activator, GlcNAc6P. On the other hand, the F174A mutant of NagB, which requires higher concentrations of GlcNAc6P for activity in vitro, grew better on GlcN in the presence of GlcNAc6P. However, wild-type NagB behaves as if it is already fully allosterically activated during growth on GlcN, and we present evidence suggesting that sufficient GlcNAc6P for allosteric activation is derived from the recycling of peptidoglycan.
authors.affiliation: Institut de Biologie Physico-Chimique, (UPR9073-CNRS), 13 rue Pierre et Marie Curie, 75005 Paris, France.
authors.forename: Laura I
authors.initials: LI
authors.lastname: Alvarez-Añorve
authors.forename: Ismael
authors.initials: I
authors.lastname: Bustos-Jaimes
authors.forename: Mario L
authors.initials: ML
authors.lastname: Calcagno
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Plumbridge
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism*; D000494:Allosteric Regulation / Q000502:physiology; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology* / Q000254:growth & development* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005944:Glucosamine / Q000378:metabolism*; D009154:Mutation; D010457:Peptidoglycan / Q000378:metabolism
chemical_list: D003470:Culture Media; D010457:Peptidoglycan; C010004:N-acetylglucosamine 6-phosphate; C020582:glucosamine-6-phosphate isomerase; D019747:Aldose-Ketose Isomerases; D005944:Glucosamine; D000117:Acetylglucosamine
references.citation: Nucleic Acids Res. 2008 May;36(8):2570-80
references.pmid: 18334534
references.citation: J Bacteriol. 1996 May;178(9):2629-36
references.pmid: 8626331
references.citation: Biochem J. 1968 Feb;106(4):847-58
references.pmid: 4866432
references.citation: Mol Microbiol. 1991 Aug;5(8):2053-62
references.pmid: 1766379
references.citation: J Bacteriol. 1990 May;172(5):2728-35
references.pmid: 2158978
references.citation: Arch Biochem Biophys. 2001 Oct 15;394(2):156-60
references.pmid: 11594728
references.citation: J Bacteriol. 2009 Sep;191(18):5641-7
references.pmid: 19617367
references.citation: J Biol Chem. 2005 May 20;280(20):19649-55
references.pmid: 15755726
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
references.pmid: 10829079
references.citation: Biochemistry. 2001 Aug 28;40(34):10187-96
references.pmid: 11513596
references.citation: Mol Microbiol. 1989 Apr;3(4):505-15
references.pmid: 2668691
references.citation: FEBS Lett. 2003 Sep 11;551(1-3):63-70
references.pmid: 12965206
references.citation: J Bacteriol. 1968 Feb;95(2):578-84
references.pmid: 4867747
references.citation: Arch Biochem Biophys. 1997 Apr 15;340(2):338-46
references.pmid: 9143339
references.citation: EMBO J. 1995 Aug 15;14(16):3958-65
references.pmid: 7545108
references.citation: PLoS Biol. 2008 Mar 18;6(3):e64
references.pmid: 18351803
references.citation: Biochemistry. 2006 Jan 31;45(4):1183-93
references.pmid: 16430214
references.citation: J Mol Biol. 2002 May 24;319(1):183-9
references.pmid: 12051945
references.citation: Mol Microbiol. 1992 May;6(9):1219-29
references.pmid: 1375310
references.citation: Arch Biochem Biophys. 1992 Sep;297(2):213-20
references.pmid: 1497340
references.citation: Curr Opin Microbiol. 2002 Apr;5(2):187-93
references.pmid: 11934616
references.citation: Microbiol Mol Biol Rev. 2008 Jun;72(2):211-27, table of contents
references.pmid: 18535144
references.citation: Mol Microbiol. 2007 Sep;65(6):1518-33
references.pmid: 17824929
references.citation: Biochemistry. 2005 Feb 1;44(4):1127-35
references.pmid: 15667206
references.citation: J Gen Microbiol. 1992 May;138(5):1011-7
references.pmid: 1645125
references.citation: J Bacteriol. 1999 Jan;181(1):47-54
references.pmid: 9864311
references.citation: Mol Microbiol. 1998 Jan;27(2):369-80
references.pmid: 9484892
references.citation: J Biol Chem. 1993 May 5;268(13):9206-14
references.pmid: 7683645
references.citation: Mol Microbiol. 1998 Jan;27(2):381-90
references.pmid: 9484893
references.citation: J Mol Biol. 1965 May;12:88-118
references.pmid: 14343300
references.citation: Mol Microbiol. 2008 Jan;67(2):364-77
references.pmid: 18067539
references.citation: Biochim Biophys Acta. 1984 Jun 14;787(2):165-73
references.pmid: 6375729
references.citation: J Bacteriol. 2005 May;187(9):2974-82
references.pmid: 15838023