Possible involvement of Lys603 from <i>Escherichia coli</i> glucosamine‐6‐phosphate synthase in the binding of its substrate fructose 6‐phosphate

Golinelli‐Pimpaneau, Béatrice; Badet, Bernard

doi:10.1111/j.1432-1033.1991.tb16271.x

Cited by 35 publications

(18 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4,7 The C-tail has been shown to form the major part of the channel and contains catalytic Lys603, which was proposed to form a Schiff base with the C2 carbonyl group of Fru6P in the first step of catalysis to facilitate amination by ammonia. 11 In addition, the main-chain backbone of the Lys503 # -His504 # -Gly505 # tripeptide (His-loop) of the neighboring synthase domain contributes to the sugar- binding pocket. The His-loop contains catalytic His504 # , which has been proposed to be involved in the ring opening of Fru6P.…”

Section: Discussionmentioning

confidence: 99%

Ordering of C-terminal Loop and Glutaminase Domains of Glucosamine-6-Phosphate Synthase Promotes Sugar Ring Opening and Formation of the Ammonia Channel

Mouilleron

Badet‐Denisot

Golinelli‐Pimpaneau

2008

Journal of Molecular Biology

View full text Add to dashboard Cite

Glucosamine-6-phosphate synthase (GlmS) channels ammonia from glutamine at the glutaminase site to fructose 6-phosphate (Fru6P) at the synthase site. Escherichia coli GlmS is composed of two C-terminal synthase domains that form the dimer interface and two N-terminal glutaminase domains at its periphery. We report the crystal structures of GlmS alone and in complex with the glucosamine-6-phosphate product at 2.95 A and 2.9 A resolution, respectively. Surprisingly, although the whole protein is present in this crystal form, no electron density for the glutaminase domain was observed, indicating its mobility. Comparison of the two structures with that of the previously reported GlmS-Fru6P complex shows that, upon sugar binding, the C-terminal loop, which forms the major part of the channel walls, becomes ordered and covers the synthase site. The ordering of the glutaminase domains likely follows Fru6P binding by the anchoring of Trp74, which acts as the gate of the channel, on the closed C-terminal loop. This is accompanied by a major conformational change of the side chain of Lys503# of the neighboring synthase domain that strengthens the interactions of the synthase domain with the C-terminal loop and completely shields the synthase site. The concomitant conformational change of the Lys503#-Gly505# tripeptide places catalytic His504# in the proper position to open the sugar and buries the linear sugar, which is now in the vicinity of the catalytic groups involved in the sugar isomerization reaction. Together with the previously reported structures of GlmS in complex with Fru6P or glucose 6-phosphate and a glutamine analogue, the new structures reveal the structural changes occurring during the whole catalytic cycle.

show abstract

Section: Discussionmentioning

confidence: 99%

Ordering of C-terminal Loop and Glutaminase Domains of Glucosamine-6-Phosphate Synthase Promotes Sugar Ring Opening and Formation of the Ammonia Channel

Mouilleron

Badet‐Denisot

Golinelli‐Pimpaneau

2008

Journal of Molecular Biology

View full text Add to dashboard Cite

show abstract

“…The first one is thought to participate in ring opening, and the second, in a proton transfer reaction between C1 and C2 (26,27). Lys-603, known to form a Schiff base with fructose 6-phosphate in glucosamine-6-phosphate synthase (29), is not conserved in the deglycase, which suggests that Schiff base formation in the reverse deglycase reaction occurs directly with the epsilon amine of the substrate.…”

Section: Discussionmentioning

confidence: 99%

Identification of a Pathway for the Utilization of the Amadori Product Fructoselysine in Escherichia coli

Wiame¹,

Delpierre

Collard

et al. 2002

Journal of Biological Chemistry

131

144

View full text Add to dashboard Cite

Escherichia coli was found to grow on fructoselysine as an energetic substrate at a rate of about one-third of that observed with glucose. Extracts of cells grown on fructoselysine catalyzed in the presence of ATP the phosphorylation of fructoselysine and a delayed formation of glucose 6-phosphate from this substrate. Data base searches allowed us to identify an operon containing a putative kinase (YhfQ) belonging to the PfkB/ ribokinase family, a putative deglycase (YhfN), homologous to the isomerase domain of glucosamine-6-phosphate synthase, and a putative cationic amino acid transporter (YhfM). The proteins encoded by YhfQ and YhfN were overexpressed in E. coli, purified, and shown to catalyze the ATP-dependent phosphorylation of fructoselysine to a product identified as fructoselysine 6-phosphate by 31 P NMR (YhfQ), and the reversible conversion of fructoselysine 6-phosphate and water to lysine and glucose 6-phosphate (YhfN). The K m of the kinase for fructoselysine amounted to 18 M, and the K m of the deglycase for fructoselysine 6-phosphate, to 0.4 mM. A value of 0.15 M was found for the equilibrium constant of the deglycase reaction. The kinase and the deglycase were both induced when E. coli was grown on fructoselysine and then reached activities sufficient to account for the rate of fructoselysine utilization.Fructosamines are the products of a non-enzymatic reaction of glucose with primary amines followed by an Amadori rearrangement. These reactions, known as glycation (to be distinguished from glycosylation, which is enzymatically catalyzed), typically modify the amino terminus and the lysine side-chains of proteins (reviewed in Refs.

show abstract

“…Two such residues, Cys-1, the only catalytic residue located at the glutamine-binding domain, and Lys-608, participating in sugar phosphate isomerization at the Fru-6-P-binding domain, were previously unequivocally identified in E. coli GlcN-6-P synthase (2,39). Since the C. albicans enzyme was effectively protected by glutamine against inactivation caused by cysteine-directed reagents, NTCB and IAA, and by Fru-6-P against lysine-directed PLP and, on the other hand, respective Cys-1 and Lys-708 residues are present in the highly conserved regions of the fungal protein (9), there is little doubt that these residues were actually modified in our experiments and play the same role as in the bacterial enzyme.…”

Section: Timementioning

confidence: 99%

Oligomeric Structure and Regulation of Candida albicans Glucosamine-6-phosphate Synthase

Milewski

Kuszczak

Jedrzejczak

et al. 1999

Journal of Biological Chemistry

View full text Add to dashboard Cite

Candida albicans glucosamine-6-phosphate (GlcN-6-P) synthase was purified to apparent homogeneity with 52% yield from recombinant yeast YRSC-65 cells efficiently overexpressing the GFA1 gene. The pure enzyme exhibited K m(Gln) ‫؍‬ 1.56 mM and K m(Fru-6-P) ‫؍‬ 1.41 mM and catalyzed GlcN-6-P formation with k cat ‫؍‬ 1150 min ؊1 . The isoelectric point of 4.6 ؎ 0.05 was estimated from isoelectric chromatofocusing. Gel filtration, native polyacrylamide gel electrophoresis, subunit cross-linking, and SDS-polyacrylamide gel electrophoresis showed that the native enzyme was a homotetramer of 79.5-kDa subunits, with an apparent molecular mass of 330 -340 kDa. Results of chemical modification of the enzyme by group-specific reagents established an essential role of a cysteinyl residue at the glutamine-binding site and histidyl, lysyl, arginyl, and tyrosyl moieties at the Fru-6-Pbinding site. GlcN-6-P synthase in crude extract was effectively inhibited by UDP-GlcNAc (IC 50 ‫؍‬ 0.67 mM). Purification of the enzyme markedly decreased the sensitivity to the inhibitor, but this could be restored by addition of another effector, glucose 6-phosphate. Binding of UDP-GlcNAc to the pure enzyme in the presence of Glc-6-P showed strong negative cooperativity, with n H ‫؍‬ 0.54, whereas in the absence of this sugar phosphate no cooperative effect was observed. Pure enzyme was a substrate for cAMP-dependent protein kinase, the action of which led to the substantial increase of GlcN-6-P synthase activity, correlated with an extent of protein phosphorylation. The maximal level of activity was observed for the enzyme molecules containing 1.21 ؎ 0.08 mol of phosphate/mol of GlcN-6-P synthase. Monitoring of GlcN-6-P synthase activity and its sensitivity to UDP-GlcNAc during yeast 3 mycelia transformation of C. albicans cells, under in situ conditions, revealed a marked increase of the former and a substantial fall of the latter.

show abstract

Possible involvement of Lys603 from Escherichia coli glucosamine‐6‐phosphate synthase in the binding of its substrate fructose 6‐phosphate

Cited by 35 publications

References 29 publications

Ordering of C-terminal Loop and Glutaminase Domains of Glucosamine-6-Phosphate Synthase Promotes Sugar Ring Opening and Formation of the Ammonia Channel

Ordering of C-terminal Loop and Glutaminase Domains of Glucosamine-6-Phosphate Synthase Promotes Sugar Ring Opening and Formation of the Ammonia Channel

Identification of a Pathway for the Utilization of the Amadori Product Fructoselysine in Escherichia coli

Oligomeric Structure and Regulation of Candida albicans Glucosamine-6-phosphate Synthase

Contact Info

Product

Resources

About