title: The crystal structure of the cysteine protease Xylellain from Xylella fastidiosa reveals an intriguing activation mechanism.
abstract: Xylella fastidiosa is responsible for a wide range of economically important plant diseases. We report here the crystal structure and kinetic data of Xylellain, the first cysteine protease characterized from the genome of the pathogenic X. fastidiosa strain 9a5c. Xylellain has a papain-family fold, and part of the N-terminal sequence blocks the enzyme active site, thereby mediating protein activity. One novel feature identified in the structure is the presence of a ribonucleotide bound outside the active site. We show that this ribonucleotide plays an important regulatory role in Xylellain enzyme kinetics, possibly functioning as a physiological mediator.
authors: Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP 13566-590, Brazil.
authors: Ney Ribeiro
authors: NR
authors: Leite
authors: Aline Regis
authors: AR
authors: Faro
authors: Maria Amélia Oliva
authors: MA
authors: Dotta
authors: Livia Maria
authors: LM
authors: Faim
authors: Andreia
authors: A
authors: Gianotti
authors: Flavio Henrique
authors: FH
authors: Silva
authors: Glaucius
authors: G
authors: Oliva
authors: Otavio Henrique
authors: OH
authors: Thiemann
mesh_terms: D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000819:agonists / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D055162:Biocatalysis; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D057056:Cysteine Proteases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004789:Enzyme Activation; D007700:Kinetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D017354:Point Mutation; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D014530:Uridine Diphosphate / Q000737:chemistry / Q000378:metabolism; D044167:Xylella / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D015853:Cysteine Proteinase Inhibitors; D050505:Mutant Proteins; D011994:Recombinant Proteins; D014530:Uridine Diphosphate; D057056:Cysteine Proteases