Core 2 sequence

Generally, the number of the shell chains in a microsphere ranges from a few hundred to a few thousand. The range of the diameter of the core is from 10-100 nm. Such a core-shell structure is very similar to the (AB)n type star block copolymers, which have many arms and spherical polymer micelles of the block or graft copolymers formed in selective solvents that are good for the corona sequence and bad for the core sequence. In fact, many theoretical investigations of the chain con-... 

Ponnazhagan and Kwon (1992) reported a putative tissue-specific ds-element (TE-1) located at-236 bp of the mouse tyrosinase promoter. They partially purified a TE-1 binding protein (approximately 49 kDa in size), but tissue specificity remains to be confirmed by a more detailed analysis. For the human tyrosinase promoter, Shibata et al. (1992) identified a 200-bp pigment cell-specific enhancer, located between -2.0 and -1.8 kb. A minimum core sequence of 39 bp was shown to be sufficient to confer the specific activity, although other regions (not identified so far) within the 200-bp fragment are required for more efficient expression in melanoma cells (Shibata et al., 1992). 

Figure 4.5. Integrative and excisive X phage recombination pathways. Integration is catalyzed by the X Int protein in a reaction that also requires the E. coli IHF protein. Recombination occurs within a common core sequence of 15 base pairs. The excision reaction requires the X Xis protein in addition to Int and IHF.

The Backbone and Core Sequences Found in Human Mucins1... 

This deletion and mutation analysis of the promoter resulted in the identification of a region located between —140 and —100, relative to the transcription start, the Anaerobic Responsive Element (ARE), which was critical for anaerobic gene expression. Two subregions exist within this promoter, both of which are necessary for activity, and each of these two subregions contained a core sequence T/CGGTTT. 

The same core sequence T/CGGTTT was identified in a number of other anaerobically inducible genes (Dennis et al., 1987). In the aldolase (Dennis et al., 1988a) and pea Adh genes (Llewellyn et al., 1987) these same sequences were shown to lie in a region which was functionally important as determined by deletion analysis. 

Table 1 NRPS Core Sequences and Their Conservation in ACV Synthetases... 

Domains and their respective core sequences are taken from Ref. 38 for clarity, multiple residues in one position have been listed on a second line. b Bold residues are altered with respect to the defined core sequences. 

R Dieckmann, M Pavela-Vrancic, E Pfeifer, El von Dohren, El Kleinkauf. The ade-nylation domain of tyrocidine synthetase 1 structural and functional role of the interdomain linker region and the (S/T)GT(T/S)GXPKG core sequence. Eur J Biochem 247 1074-1082, 1997. 

EMBL Nucleotide Sequence Database. SWISS-PROT consists of core sequence data with minimal redundancy, citation and extensive annotations including protein function, post-translational modifications, domain sites, protein structural information, diseases associated with protein deficiencies and variants. SWISS-PROT and TrEMBL are available at EBI site, http //www.ebi.ac.uk/swissprot/, and ExPASy site, http //www.expasy.ch/sprot/. From the SWISS-PROT and TrEMBL page of ExPASy site, click Full text search (under Access to SWISS-PROT and TrEMBL) to open the search page (Figure 11.3). Enter the keyword string (use Boolean expression if required), check SWISS-PROT box, and click the Submit button. Select the desired entry from the returned list to view the annotated sequence data in Swiss-Prot format. An output in the fasta format can be requested. Links to BLAST, feature table, some ExPASy proteomic tools (e.g., Compute pI/Mw, ProtParam, ProfileScan, ProtScale, PeptideMass, ScanProsite), and structure (SWISS-MODEL) are provided on the page. 

Fig. 1 Comparison of Streptavidin and avidin. a Conserved primary amino acid core sequences of streptavidin and avidin (Taken from [8]). b Overlay of peptide backbones of streptavidin and avidin monomers (Taken from [14])...

The leucokinins (LK s) are a new class of insect myotropic neuropeptides isolated from head extracts of the cockroach L. maderae. These octapeptides all contain a similar core sequence of 5 amino acids that extend from position 4 through 8. This sequence Phe-X-Ser-Trp-Gly-NH2 seems to be required for hindgut stimulation. The initial response of the hindgut to the LK s was characterized by an increase in the frequency and/or amplitude of phasic contractions (50, ). At higher peptide concentrations, a tonic component was generally present. All of the LK s showed a response at 3 x 10 M that was 5-10% above the mean level of spontaneous activity. The maximum response for each of the peptides was recorded at a concentration 2.1 X 10" M. Thus, the intrinsic activities for the LK s are nearly equal because the dose-response curves have about the same asymptotic limits. A comparison of the dose concentrations that gave a half maximal response (ED q) for the 8 peptides is shown in Table I. 

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