Tài liệu Báo cáo khoa học: Directed evolution of trimethoprim resistance inEscherichia coli doc

... indicated. Directed evolution in E. coli M. Watson et al. 2666 FEBS Journal 274 (2007) 2661–2671 ª 2007 The Authors Journal compilation ª 2007 FEBS Directed evolution of trimethoprim resistance in ... [5]. Because of its central role in one-carbon metabo- lism, dihydrofolate reductase (DHFR) has long been a Keywords antibiotic resistance; dihydrofolate reductase; directed...

Ngày tải lên: 19/02/2014, 02:20

... 3¢- UTR of vertebrate DNase I cDNA lengthened about twofold during the evolutionary stage between amphibians and reptiles. Structural features of shark DNases I The amino acid sequences of the ... r lysates of cells that had been transfected with expression vectors containing the entire coding regions of the wild-type shark DNases I, substitution of the signal sequence regions of...

Ngày tải lên: 19/02/2014, 16:20

... several cases, mod- erate resistance is imparted by mutations of the target enzyme (target-site mechanism of resistance) [60], but there is, as yet, no documented case of a plant species having ... molecular mode of action of glypho- sate and the molecular basis for glyphosate resistance. Structure and function of EPSPS EPSPS catalyzes the transfer of the enolpyruvyl moiety...

Ngày tải lên: 14/02/2014, 14:20

... problem of unscrambling English affixes. The role of affixes is crucial in the study of word-breaking practice. In the automatic determination of the parts of speech (a central feature of automatic ... determination of parts -of- speech assignments E. The determination of the number of phonetic syl- lables corresponding to a written English word In the first case, we hav...

Ngày tải lên: 19/02/2014, 19:20

... classification of the weak suffixes by degree of weakness as a means of approaching the suffix-in- context problem. Table 2, which reviews the prefixes and suffixes de- fined by Resnikoff and Dolby, ... English," an algorithm for the structural definition of affixes was developed and applied to data consisting of all the words of the form CVCVC in the Shorter Oxford Dict...

Ngày tải lên: 19/02/2014, 19:20

... f'mite set of symbols, so there is only a finite number of strings of given length L, and it has a finite number of rules, so there is only a finite number of possible parse trees of given depth ... representation for the set of pairs of ground terms [A,B] such that (A > B) is a rule in the ground grammar of G'. Clearly this representation is just the set...

Ngày tải lên: 21/02/2014, 20:20

... effect of chloride ions on enzyme activity was investigated (Fig. 4). The hydrolysis of Mca- Fig. 3. Role of His505 and His345 in catalysis. Schematic of the proposed reaction intermediate of ACE2, ... study has highlighted the importance of Arg273 in binding of the C-terminus of peptide substrates by ACE2. The complete loss of activity observed as a result of replacing th...

Ngày tải lên: 20/02/2014, 01:20

... revealed tau bands of  64 kDa in the GST–Fyn- SH3-bound fraction from cells transfected with each of the tau constructs. Densitometric analysis of Fyn-SH3- bound tau as a proportion of that in corresponding cell ... this band was not apparent on western blots of lysates of Y394F tau (Fig. 2A). The absence of this larger species could indi- cate that phosphorylation of tau by...

Ngày tải lên: 14/02/2014, 14:20

... surface of the molecule and is rather far away from the trinuclear site. Therefore, the C-terminal sequence of RlL might be more of an evolu- tionary relic than a functional feature of the enzyme. The ... molecules A and B (and C and D) of the asymmetric unit form a weak dimer (Fig . 6). On the basis of calculations performed Fig. 6. (A) Cartoon representation of dimers of TaL...

Ngày tải lên: 14/02/2014, 18:20

... reservoir consisted of 500 lL of 0.7 m sodium citrate, 10 mm dithiothreitol and 70 mm Hepes at pH 7.4. Drops consisted of 0.75 l L of importin-a (70-529) at 18 mgÆmL )1 , 0.75 lL of CLIC4 NLS peptide ... Indicative of the tightness of the fit, there are a large number (30) of atom-to-atom van der Waals’ contacts between the Tyr205 side chain and importin-a (Table 2). The num- b...

Ngày tải lên: 14/02/2014, 19:20