1. Crystal structures and functional studies clarify substrate selectivity and catalytic residues for the unique orphan enzyme N-acetyl-D-mannosamine dehydrogenase.

    Biochemical Journal 462(3):499 (2014) PMID 24969681

    NAMDH (N-acetyl-D-mannosamine dehydrogenase), from the soil bacteroidete Flavobacterium sp. 141-8, catalyses a rare NAD+-dependent oxidation of ManNAc (N-acetyl-D-mannosamine) into N-acetylmannosamino-lactone, which spontaneously hydrolyses into N-acetylmannosaminic acid. NAMDH belongs to the SD...
  2. Developments in optics and performance at BL13-XALOC, the macromolecular crystallography beamline at the ALBA synchrotron.

    Journal of Synchrotron Radiation 21(Pt 4):679 (2014) PMID 24971961 PMCID PMC4073956

    BL13-XALOC is currently the only macromolecular crystallography beamline at the 3 GeV ALBA synchrotron near Barcelona, Spain. The optics design is based on an in-vacuum undulator, a Si(111) channel-cut crystal monochromator and a pair of KB mirrors. It allows three main operation modes: a focuse...
  3. First functional and mutational analysis of group 3 N-acetylneuraminate lyases from Lactobacillus antri and Lactobacillus sakei 23K.

    PLoS ONE 9(5):e96976 (2014) PMID 24817128 PMCID PMC4016182

    N-acetyl neuraminate lyases (NALs) catalyze the reversible aldol cleavage of N-acetyl neuraminic acid (Neu5Ac) to pyruvate and N-acetyl-D-mannosamine (ManNAc). Previous phylogenetic studies divided NALs into four different groups. Groups 1 and 2 have been well characterized at both kinetic and m...
  4. First functional and mutational analysis of group 3 N-acetylneuraminate lyases from Lactobacillus antri and Lactobacillus sakei 23K.

    PLoS ONE 9(5):e96976 (2014) PMID 24817128 PMCID PMC4016182

    N-acetyl neuraminate lyases (NALs) catalyze the reversible aldol cleavage of N-acetyl neuraminic acid (Neu5Ac) to pyruvate and N-acetyl-D-mannosamine (ManNAc). Previous phylogenetic studies divided NALs into four different groups. Groups 1 and 2 have been well characterized at both kinetic and m...
  5. Insight on an arginine synthesis metabolon from the tetrameric structure of yeast acetylglutamate kinase.

    PLoS ONE 7(4):e34734 (2012) PMID 22529931 PMCID PMC3329491

    N-acetyl-L-glutamate kinase (NAGK) catalyzes the second, generally controlling, step of arginine biosynthesis. In yeasts, NAGK exists either alone or forming a metabolon with N-acetyl-L-glutamate synthase (NAGS), which catalyzes the first step and exists only within the metabolon. Yeast NAGK (yN...
  6. New insight into the transcarbamylase family: the structure of putrescine transcarbamylase, a key catalyst for fermentative utilization of agmatine.

    PLoS ONE 7(2):e31528 (2012) PMID 22363663 PMCID PMC3282769

    Transcarbamylases reversibly transfer a carbamyl group from carbamylphosphate (CP) to an amine. Although aspartate transcarbamylase and ornithine transcarbamylase (OTC) are well characterized, little was known about putrescine transcarbamylase (PTC), the enzyme that generates CP for ATP producti...
  7. The crystal structure of the cephalosporin deacetylating enzyme acetyl xylan esterase bound to paraoxon explains the low sensitivity of this serine hydrolase to organophosphate inactivation.

    Biochemical Journal 436(2):321 (2011) PMID 21382014

    Organophosphorus insecticides and nerve agents irreversibly inhibit serine hydrolase superfamily enzymes. One enzyme of this superfamily, the industrially important (for β-lactam antibiotic synthesis) AXE/CAH (acetyl xylan esterase/cephalosporin acetyl hydrolase) from the biotechnologically valu...
  8. Erratum to “Two crystal structures ofEscherichia coli N-acetyl-l-glutamate kinase demonstrate the cycling between open and closed conformations” [J. Mol. Biol. 399/3 (2010) 476–490]

    Journal of Molecular Biology 407(4):621 (2011)

  9. Two crystal structures of Escherichia coli N-acetyl-L-glutamate kinase demonstrate the cycling between open and closed conformations.

    Journal of Molecular Biology 399(3):476 (2010) PMID 20403363

    N-Acetyl-L-glutamate kinase (NAGK), the paradigm enzyme of the amino acid kinase family, catalyzes the second step of arginine biosynthesis. Although substrate binding and catalysis were clarified by the determination of four crystal structures of the homodimeric Escherichia coli enzyme (EcNAGK)...
  10. Substrate binding and catalysis in carbamate kinase ascertained by crystallographic and site-directed mutagenesis studies: movements and significance of a unique globular subdomain of this key enzyme for fermentative ATP production in bacteria.

    Journal of Molecular Biology 397(5):1261 (2010) PMID 20188742

    Carbamate kinase (CK) makes ATP from ADP and carbamoyl phosphate (CP) in the final step of the microbial fermentative catabolism of arginine, agmatine, and oxalurate/allantoin. Two previously reported CK structures failed to clarify CP binding and catalysis and to reveal the significance of the ...
  11. Two Crystal Structures ofEscherichia coli N-Acetyl-l-Glutamate Kinase Demonstrate the Cycling between Open and Closed Conformations

    Journal of Molecular Biology 399(3):476 (2010)

    N-Acetyl- l-glutamate kinase (NAGK), the paradigm enzyme of the amino acid kinase family, catalyzes the second step of arginine biosynthesis. Although substrate binding and catalysis were clarified by the determination of four crystal structures of the homodimeric Escher...
  12. Improved cross-linked enzyme aggregates for the production of desacetyl β-lactam antibiotics intermediates

    Bioresource Technology 101(1):331 (2010)

    Cross-linked enzyme aggregates (CLEAs) are reported for the first time for a recombinant acetyl xylan esterase (AXE) from Bacillus pumilus. With this enzyme, CLEAs production was most effective using 3.2 M (80%-saturation) ammonium sulfate, followed by cross-linking for 3 ...
  13. Improved cross-linked enzyme aggregates for the production of desacetyl beta-lactam antibiotics intermediates.

    Bioresource Technology 101(1):331 (2010) PMID 19733060

    Cross-linked enzyme aggregates (CLEAs) are reported for the first time for a recombinant acetyl xylan esterase (AXE) from Bacillus pumilus. With this enzyme, CLEAs production was most effective using 3.2M (80%-saturation) ammonium sulfate, followed by cross-linking for 3h with 1% (v/v) glutarald...
  14. Substrate Binding and Catalysis in Carbamate Kinase Ascertained by Crystallographic and Site-Directed Mutagenesis Studies: Movements and Significance of a Unique Globular Subdomain of This Key Enzyme for Fermentative ATP Production in Bacteria

    Journal of Molecular Biology 397(5):1261 (2010)

    Carbamate kinase (CK) makes ATP from ADP and carbamoyl phosphate (CP) in the final step of the microbial fermentative catabolism of arginine, agmatine, and oxalurate/allantoin. Two previously reported CK structures failed to clarify CP binding and catalysis and to reveal the significance of...
  15. The crystal structure of the complex of PII and acetylglutamate kinase reveals how PII controls the storage of nitrogen as arginine.

    PNAS 104(45):17644 (2007) PMID 17959776 PMCID PMC2077032

    Photosynthetic organisms can store nitrogen by synthesizing arginine, and, therefore, feedback inhibition of arginine synthesis must be relieved in these organisms when nitrogen is abundant. This relief is accomplished by the binding of the PII signal transduction protein to acetylglutamate kina...
  16. A novel two-domain architecture within the amino acid kinase enzyme family revealed by the crystal structure of Escherichia coli glutamate 5-kinase.

    Journal of Molecular Biology 367(5):1431 (2007) PMID 17321544

    Glutamate 5-kinase (G5K) makes the highly unstable product glutamyl 5-phosphate (G5P) in the initial, controlling step of proline/ornithine synthesis, being feedback-inhibited by proline or ornithine, and causing, when defective, clinical hyperammonaemia. We determined two crystal structures of ...
  17. A Novel Two-domain Architecture Within the Amino Acid Kinase Enzyme Family Revealed by the Crystal Structure ofEscherichia coliGlutamate 5-kinase

    Journal of Molecular Biology 367(5):1431 (2007)

    Glutamate 5-kinase (G5K) makes the highly unstable product glutamyl 5-phosphate (G5P) in the initial, controlling step of proline/ornithine synthesis, being feedback-inhibited by proline or ornithine, and causing, when defective, clinical hyperammonaemia. We determined two crystal structure...
  18. Structural Bases of Feed-back Control of Arginine Biosynthesis, Revealed by the Structures of Two HexamericN-Acetylglutamate Kinases, fromThermotoga maritimaandPseudomonas aeruginosa

    Journal of Molecular Biology 356(3):695 (2006) PMID 16376937

    N-Acetylglutamate kinase (NAGK) catalyses the second step in the route of arginine biosynthesis. In many organisms this enzyme is inhibited by the final product of the route, arginine, and thus plays a central regulatory role. In addition, in photosynthetic organisms NAGK is the targ...
  19. The crystal structure of Pyrococcus furiosus UMP kinase provides insight into catalysis and regulation in microbial pyrimidine nucleotide biosynthesis.

    Journal of Molecular Biology 352(2):438 (2005) PMID 16095620

    UMP kinase (UMPK), the enzyme responsible for microbial UMP phosphorylation, plays a key role in pyrimidine nucleotide biosynthesis, regulating this process via feed-back control and via gene repression of carbamoyl phosphate synthetase (the first enzyme of the pyrimidine biosynthesis pathway). ...
  20. The Crystal Structure ofPyrococcus furiosusUMP Kinase Provides Insight into Catalysis and Regulation in Microbial Pyrimidine Nucleotide Biosynthesis

    Journal of Molecular Biology 352(2):438 (2005)

    UMP kinase (UMPK), the enzyme responsible for microbial UMP phosphorylation, plays a key role in pyrimidine nucleotide biosynthesis, regulating this process via feed-back control and via gene repression of carbamoyl phosphate synthetase (the first enzyme of the pyrimidine bios...