KAl(SO4)2.12H2O is found to efficiently and heterogeneously catalyze the one-pot three-component reaction of 2-(nitromethylene)imidazolidine, malononitrile and aldehydes under mild conditions to afford the corresponding tetrahydroimidazo[1,2-a]pyridine in good yields and short reaction times. Docking  study  of  some  compounds  in  the  active  site  of  α-glucosidase demonstrated  that  these...

Soluble guanylate cyclase (sGC) catalyses the synthesis of cyclic GMP in response to nitric oxide. The enzyme is a heterodimer of homologous α and β subunits, each of which is composed of multiple domains. We present here crystal structures of a heterodimer of the catalytic domains of the α and β subunits, as well as an inactive homodimer of β subunits. This first structure of a metazoan, heter...

Staphylococcus hyicus lipase differs from other bacterial lipases in its high phospholipase A1 activity. Here, we present the crystal structure of the S. hyicus lipase at 2.86 A resolution. The lipase is in an open conformation, with the active site partly covered by a neighbouring molecule. Ser124, Asp314 and His355 form the catalytic triad. The substrate-binding cavity contains two large hydr...

Visual function in vertebrates is dependent on the membrane-bound retinoid isomerase RPE65, an essential component of the retinoid cycle pathway that regenerates 11-cis-retinal for rod and cone opsins. The mechanism by which RPE65 catalyzes stereoselective retinoid isomerization has remained elusive because of uncertainty about how retinoids bind to its active site. Here we present crystal stru...

The L-2-haloacid dehalogenase from the 1,2-dichloroethane degrading bacterium Xanthobacter autotrophicus GJ10 catalyzes the hydrolytic dehalogenation of small L-2-haloalkanoic acids to yield the corresponding D-2-hydroxyalkanoic acids. Its crystal structure was solved by the method of multiple isomorphous replacement with incorporation of anomalous scattering information and solvent flattening,...

Human immunodeficiency virus type 1 (HIV-1) protease inhibitors comprise an important class of drugs used in HIV treatments. However, mutations of protease genes accelerated by low fidelity of reverse transcriptase yield drug resistant mutants of reduced affinities for the inhibitors. This problem is considered to be a serious barrier against HIV treatment for the foreseeable future. In this st...

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A desaturase with 83% sequence identity to the coriander delta(4)-16:0-ACP desaturase was isolated from developing seeds of Hedera helix (English ivy). Expression of the ivy desaturase in Arabidopsis resulted in the accumulation of 16:1delta(4) and its expected elongation product 18:1delta(6) (petroselinic acid). Expression in Escherichia coli resulted in the accumulation of soluble, active pro...

thioredoxins (trxs) are small ubiquitous oxidoreductase proteins with two redox-active cys residues in a conserved active site (wcg/ppc) that regulate numerous target proteins via thiol/disulfide exchanges in the cells of prokaryotes and eukaryotes. the isoforms ostrx23 with a typical active site (wcgpc) and ostrx20 with an atypical active site (wctpc) are two  trx h- type isoforms in rice that ...