Unique aliphatic amidase from a psychrotrophic and haloalkal

Details of Research

TitleUnique aliphatic amidase from a psychrotrophic and haloalkaliphilic Nesterenkonia isolateAbstractNesterenkonia strain AN1 was isolated from a screening program for nitrile- and amide-hydrolyzing microorganisms in Antarctic desert soil samples. Strain AN1 showed significant 16S rRNA sequence identity to known members of the genus. Like known Nesterenkonia species, strain AN1 was obligately alkaliphilic (optimum environmental pH, 9 to 10) and halotolerant (optimum environmental Na+ content, 0 to 15% [wt/vol]) but was also shown to be an obligate psychrophile with optimum growth at approximately 21Â DegreesC. The partially sequenced genome of AN1 revealed an open reading frame (ORF) encoding a putative protein member of the nitrilase superfamily, referred to as NitN (264 amino acids). The protein crystallized readily as a dimer and the atomic structure of all but 10 amino acids of the protein was determined, confirming that the enzyme had an active site and a fold characteristic of the nitrilase superfamily. The protein was screened for activity against a variety of nitrile, carbamoyl, and amide substrates and was found to have only amidase activity. It had highest affinity for propionamide but demonstrated a low catalytic rate. NitN had maximal activity at 30Â DegreesC and between pH 6.5 and 7.5, conditions which are outside the optimum growth range for the organism. Â© 2011, American Society for Microbiology.

Details

1st AuthorNel, A. AuthorNel, A.Tuffin, I.Sewell, B.Cowan, D.Year2011JournalApplied and Environmental MicrobiologyVolume77Number11Pages3696-3702DOI10.1128/AEM.02726-10URLhttps://www.scopus.com/inward/recor.....ccacce43772250d93806adcb3Keywords16S rRNA sequencesActive siteAmidaseCarbamoylCatalytic ratesDesert soilsEnvironmental pHHaloalkaliphilicHalotolerantNitrilaseOpen reading framePutative proteinsScreening programs, AmidesAminationAmino acidsCyanidesEcologyRNASodium, Proteins, amidasebacterial DNAfatty acidribosome DNARNA 16Ssodium chloride, amino acidbacteriumcatalysisenzyme activitygenetic analysisgrowthhydrolysisionmicroorganismpHproteinsodiumsoil microorganism, amino acid sequenceAntarcticaarticlechemical structurechemistrycluster analysisDNA sequenceenzyme active siteenzyme specificityenzyme stabilityenzymologygeneticsgrowth, development and agingisolation and purificationmetabolismmicrobiologyMicrococcaceaemolecular geneticsnucleotide sequencepHphylogenyprotein multimerizationprotein quaternary structuresequence alignmenttemperatureX ray crystallography, AmidohydrolasesAmino Acid SequenceAntarctic RegionsCatalytic DomainCluster AnalysisCrystallography, X-RayDNA, BacterialDNA, RibosomalEnzyme StabilityFatty AcidsHydrogen-Ion ConcentrationMicrococcaceaeModels, MolecularMolecular Sequence DataPhylogenyProtein MultimerizationProtein Structure, QuaternaryRNA, Ribosomal, 16SSequence AlignmentSequence Analysis, DNASodium ChlorideSoil MicrobiologySubstrate SpecificityTemperature, Antarctica, Nesterenkonia

Other

CitationNel, A., Tuffin, I., Sewell, B. and Cowan, D. (2011). Unique aliphatic amidase from a psychrotrophic and haloalkaliphilic Nesterenkonia isolate. Applied and Environmental Microbiology, 77(11): 3696-3702