RESUMO
KPN03535 (gi|152972051) is a putative lipoprotein of unknown function that is secreted by Klebsiella pneumoniae MGH 78578. The crystal structure reveals that despite a lack of any detectable sequence similarity to known structures, it is a novel variant of the OB-fold and structurally similar to the bacterial Cpx-pathway protein NlpE, single-stranded DNA-binding (SSB) proteins and toxins. K. pneumoniae MGH 78578 forms part of the normal human skin, mouth and gut flora and is an opportunistic pathogen that is linked to about 8% of all hospital-acquired infections in the USA. This structure provides the foundation for further investigations into this divergent member of the OB-fold family.
Assuntos
Proteínas de Bactérias/química , Klebsiella pneumoniae/química , Lipoproteínas/química , Sequência de Aminoácidos , Cristalografia por Raios X , Modelos Moleculares , Dados de Sequência Molecular , Dobramento de Proteína , Estrutura Terciária de ProteínaRESUMO
BT1062 from Bacteroides thetaiotaomicron is a homolog of Mfa2 (PGN0288 or PG0179), which is a component of the minor fimbriae in Porphyromonas gingivalis. The crystal structure of BT1062 revealed a conserved fold that is widely adopted by fimbrial components.
Assuntos
Bacteroides/química , Proteínas de Fímbrias/química , Fímbrias Bacterianas/química , Dobramento de Proteína , Sequência de Aminoácidos , Bacteroides/genética , Cristalografia por Raios X , Proteínas de Fímbrias/genética , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Alinhamento de Sequência , Homologia Estrutural de ProteínaRESUMO
Pyridoxal-5'-phosphate or PLP, the active form of vitamin B6, is a highly versatile cofactor that participates in a large number of mechanistically diverse enzymatic reactions in basic metabolism. PLP-dependent enzymes account for â¼1.5% of most prokaryotic genomes and are estimated to be involved in â¼4% of all catalytic reactions, making this an important class of enzymes. Here, we structurally and functionally characterize three novel PLP-dependent enzymes from bacteria in the human microbiome: two are from Eubacterium rectale, a dominant, nonpathogenic, fecal, Gram-positive bacteria, and the third is from Porphyromonas gingivalis, which plays a major role in human periodontal disease. All adopt the Type I PLP-dependent enzyme fold and structure-guided biochemical analysis enabled functional assignments as tryptophan, aromatic, and probable phosphoserine aminotransferases.