Báo cáo khoa học: Mutational analysis of functional domains in Mrs2p, the mitochondrial Mg2+ channel protein of Saccharomyces cerevisiae ppt

... 2006)doi:10.1111/j.1742-4658.2006.05157.x The nuclear gene MRS2 in Saccharomyces cerevisiae encodes an integral protein (Mrs2p) of the inner mitochondrial membrane. It forms an ion channel mediating in ux of Mg2+into mitochondria. ... feature of Mrs2p is the existence of two transmembrane -domains and a short connect-ing sequence of about 7–8 amino acids. This is sup-posed to be the only part of the protein located in the intermembrane ... variants of Mrs2p, located either in mito-chondria, in the plasma membrane or in other cellularmembranes [6]. The S. cerevisiae protein Mrs2p has been shown tomediate Mg2+ in ux into mitochondria....

Tài liệu Báo cáo khoa học: Mutational analysis of plasminogen activator inhibitor-1 Interactions of a-helix F and its neighbouring structural elements regulates the activity and the rate of latency transition pdf

... linkage of the activesite Ser of the protease to the carboxyl group of P1by anester bond and insertion of the N-terminal part of the RCLas strand 4 in b-sheet A (s4A) of the serpin. Consequently, the ... behaviour of the serpin.Complex formation between serpins and their cognateproteases is fuelled by the thermodynamic properties of the serpin. Accordingly, insertion of the RCL as s4A and the ensuing ... Accordingly, we assume that the aliphatic moiety of the introduced K in PAI-1(M149K)allows the side chain to adapt the same orientation as the original M and therefore the stabilizing effect of the...

Báo cáo khoa học: Mutational analysis of substrate recognition by human arginase type I ) agmatinase activity of the N130D variant pot

... intermediate of NO synthesis [26]. On the otherhand, in contrast with Asn130 in arginase I, the corres-ponding Asn149 of arginase II was not found to be aligand for the a-carboxylate group of the transitionstate ... ligand for the a-carboxylgroup of arginine in arginase I [9,23,24]. On this basis,direct repulsion of the negatively charged Asp130would explain the increased Kmvalue for arginineinhibition ... for the a-amino group of arginine in arginase I [9], cannot be discounted. Whatever the case, the substantially low kcatvalue argues againstcorrect positioning of agmatine with respect to the metal-bound...

Báo cáo khoa học: Mutational analysis of the C-domain in nonribosomal peptide synthesis pot

... bound in the binding poc ket o f a nother e nzymemolecule within the active homomultimer. This could explain the distance in sequence homology with NRPSs C -domains displayed in the alignment of the ... [5]. Furthermore, a chromosomal pointmutatio n in srfA-B, changing a D to A in the His-motif(italic) of the corresponding Asp domain of the surfactinsynthetase was found to abolish surfactin production ... addition of 10% glycerol (v/v), the proteinscould be stored at )80 °C. Protein concentrations weredetermined using the calculated extinction coef®cients for the A280 of the proteins: 138 690M)1ácm)1for...

Báo cáo khoa học: Mutational analysis of the preferential binding of human topoisomerase I to supercoiled DNA pot

... shortened linker in the mutant enzyme destabilized the interaction between the COOH-terminal and core domains, enabling the COOH-terminal domain of one protein to occupy itsbinding site in the core ... second DNA-binding site on the protein. Fourth,clusters of basic residues in core subdomain III, and the linker on the side of the protein distal from the Cap, could mediate DNA-binding at a node.For ... missingpart of the coiled-coil linker domain could form dimersthrough a domain swapping mechanism involving the core and COOH-terminal domains of the two subunits.We hypothesized that the...

Báo cáo khoa học: Mutational analysis of a type II thioesterase associated with nonribosomal peptide synthesis pdf

... removal of short acylchains originating from aberrant decarboxylation of chainextender units from the thiol moiety of the 4¢-Ppantcofactors of acyl carrier proteins [15,16]. In NRPSs thereis ... acetyl-S-Ppant-PCP. Interestingly, after 5–10 min of incubation at 37 °C, no further hydrolysis of the remain-ing substrate was observed, indicating clear instability of this enzyme under the assay conditions ... resulting from the replacement of His with Ala rather than by directinvolvement in catalysis.To determine the identy of the remaining residue of the proposed catalytic triad, the two strictly...

Tài liệu Báo cáo khoa học: Control analysis as a tool to understand the formation of the las operon in Lactococcus lactis doc

... all the genesinvolved in the pathway in the same operon; the cellcan then respond quickly to changes in the environ-ment by changing the expression of only a few genesand using the protein- synthesizing ... by the second gene in the las operon (Fig. 1). In order to obtain strains with increased PK activity anadditional copy of the pyk gene was recombined into the TP901-1 attachment site using the ... contains only a singlepyk gene under the control of a synthetic promoter. The relative PFK activity in strain CS1929 was foundto increase to over 160% of the wild-type level,whereas the relative...

Báo cáo khoa học: Ibuprofen binding to secondary sites allosterically modulates the spectroscopic and catalytic properties of human serum heme–albumin doc

... December2010)doi:10.1111/j.1742-4658.2010.07986.x The ibuprofen primary binding site FA3–FA4 is located in domain III of human serum albumin (HSA), the secondary clefts FA2 and FA6 beingsited in domains I and II. Here, the thermodynamics of ... effects,combining the actions of ibuprofen and warfarin [8].It is worth noting that the modular architecture of HSA allows the removal of domain III without thisaffecting the conformational stability of ... stability of the remaining protein scaffold. Moreover, lost contacts between par-alogous HSA domains do not impair the correct fold-ing of single domains, as shown by the agreementbetween thermodynamic...

Báo cáo khoa học: Eukaryotic class 1 translation termination factor eRF1 ) the NMR structure and dynamics of the middle domain involved in triggering ribosome-dependent peptidyl-tRNA hydrolysis pptx

... rearrangement of the protein during the docking to the binding site on the ribosome or otherligands. Strikingly, the second most ﬂexible part of the protein (if one does not take into account the N-termi-nal ... coli in vivo can be explainedby their competitive inhibition at the ribosome-bindingsite [32].Together, the M and C domains of human eRF1, in the absence of the N domain, are able to bind to the mammalian ... 1.1H,15N-HSQC spectra of the Mdomain of human eRF1. The numbering of the residues corresponds to that of the fulleRF1 protein. (A) The Gly region of the 1H,15N-HSQC spectrum of the M domain of human...

Báo cáo khoa học: Retrocyclin RC-101 overcomes cationic mutations on the heptad repeat 2 region of HIV-1 gp41 ppt

... number of RC-101 binding conforma-tions. Docking of RC-101 to HR1 alone did not result in a strong binding energy [Fig. 2]. Conversely, the minimum energy of binding to HR2 is predominantlylower ... binding of RC-101 to HR1 and the speciﬁcbinding to HR2 seen in this work. RC-101 bindsreversibly but with high afﬁnity to glycoproteins andassociates with the cellular lipids and proteins involved in ... white in color, are exposed to the external environment in the 6HB. (C) Isoelectric points for HR1 andHR2 were obtained by inputting the group M sequences into the pI ⁄ MWtool of EXPASY. The...

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