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91.
Arabidopsis consensus intron sequences 总被引:7,自引:0,他引:7
We have analysed 998 Arabidopsis intron sequences in the EMBL database. All Arabidopsis introns to adhere to the :GU...AG: rule with the exception of 1% of introns with :GC at their 5 ends. Virtually all of the introns contained a putative branchpoint sequence (YUNAN) 18 to 60 nt upstream of the 3 splice site. Although a polypyrimidine tract was much less apparent than in vertebrate introns, the most common nucleotide in the region upstream of the 3 splice site was uridine. Consensus sequences for 5 and 3 splice sites and branchpoint sequences for Arabidopsis introns are presented. 相似文献
92.
X. B. Li C. Z. Liang H. G. Wu W. X. Zhai N. Huang L. H. Zhu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(6):702-708
A tandemly repeated DNA sequence (RRS7) was isolated from Oryza alta (CCDD). RRS7-related sequences were also found tandemly arrayed in genomes AA, BB, BBCC, CC, and EE, and a small amount of RRS7-related sequences were detected in genome FF and the Oryza species with unknown genomes. DNA sequence analysis of the 1844-bp insert of RRS7 revealed that it contained six tandemly repeated units, of which five were 155 bp in length and one was 194 bp in length and contained an imperfect internal 39-bp duplication. Southern blot analysis showed that the boundary sequence contained in RRS7 is a single-copy sequence. A 155-bp consensus sequence derived from the six monomeric repeats contained no internal repeat and showed no significant homology to other currently known sequences. The results of Southern blot and sequence analysis revealed that there are at least two subfamilies present in the RRS7 family; these are represented by the DraI site and the MspI site, respectively. Restriction digestion with two pairs of isoschizomers MboI/Sau3A and MspI/HpaII demonstrated that most of the C residues in the GATC sites and the internal C in the CCGG sites of the RRS7 family in O. Alta were methylated. The usefulness of the RRS7 family in determining the evolutionary relationship of the genome DD and other Oryza genomes is discussed. 相似文献
93.
籼稻232蜡质基因转录起始位点的鉴定 总被引:5,自引:0,他引:5
Northernblot杂交分析和蜡质基因cDNA的序列分析表明水稻蜡质基因的转录本可能延伸到翻译起始密码子(ATG)上游12kb处。据此设计了21Nt的寡核苷酸引物,并以籼稻232胚乳RNA为模板,以引物延伸法确定籼稻232蜡质基因的转录起始点,籼稻蜡质基因的转录起始旁邻顺序CTCACCA与高等植物基因的转录起始点一致顺序CTCATCA仅相差1个碱基。通过顺序比较,对东乡野生稻蜡质基因中的转录起始位点的位置,以及对此两稻种中TATA盒的可能顺序进行了讨论。 相似文献
94.
95.
Hans-Jochen Schfer Gabriele Rathgeber Achim Schuhen Richard J. Berzborn 《FEBS letters》1994,340(3):265-268
UV irradiation of the ATPase (CF1) from spinach chloroplasts in the presence of 3'-arylazido-β-alanyl-8-azido ATP (8,3'-DiN3ATP) results in a nucleotide-dependent inactivation of the enzyme and in a nucleotide-dependent formation of -β cross-links. The results demonstrate an interfacial localization of the nucleotide binding sites on CF1. 相似文献
96.
Paul D. Hempstead Aaron J. Hudson Peter J. Artymiuk Simon C. Andrews Mark J. Banfield John R. Guest Pauline M. Harrison 《FEBS letters》1994,350(2-3):258-262
X-Ray analysis of the ferritin of Escherichia coli (Ec-FTN) and of Ec-FTN crystals soaked in (NH4)2Fe(SO4)2 has revealed the presence of three iron-binding sites per subunit. Two of these form a di-iron site in the centre of the subunit as has been proposed for the ‘ferroxidase centres’ of human ferritin H chains. This di-iron site, lying within the 4-alpha-helix bundle, resemble those of ribonucleotide reductase, methane monoxygenase and haemerythrin. The third iron is bound by ligands unique to Ec-FTN on the inner surface of the protein shell. It is speculated that this state may represent the nucleation centre of a novel type of Fe(III) cluster, recently observed in Ec-FTN. 相似文献
97.
The nest site characteristics of the freshwater three-spined stickleback, Gasterosteus aculeatus (form leiurus ), were quantitatively investigated in springs and the main stream of the Yamayoke and the Tsuya River system, central Japan. Most nests (93·4%) were on a muddy or sandy substratum, at depths of 10–40 cm (84·3%), in water velocities less than 15 cm s−1 (76·2%) and in the temperature range of 14 to 16° C (82·7%), Spring-fed localities provided more of these conditions than the main stream channel and hence contained more potential nesting areas. Thus, they were utilized by male sticklebacks both temporally (prolonged breeding season) and spatially (more nest sites). 相似文献
98.
Leucrose formation from sucrose and fructose by dextransucrase is of practical interest. It has been investigated at different experimental conditions, including the influence of temperature on reaction rate and selectivity. Under appropriate conditions high product yield can be obtained. Furthermore, a model is presented that allows interpretation of the experimental data. 相似文献
99.
Mária Wollemann Judit Farkas Géza Tóth Sándor Benyhe 《Journal of neurochemistry》1994,63(4):1460-1465
Abstract: A tritiated heptapeptide, [3 H]Tyr-Gly-Gly-Phe-Met-Arg-Phe ([3 H]Met-enkephalin-Arg6 -Phe7 ), with high specific radioactivity has been synthesized in order to characterize its opioid binding activity to frog brain membrane fractions. The apparent K D value of the radioligand calculated from homologous displacement experiments was 3.4 n M , and the maximal number of specific binding sites was 630 fmol/mg of protein. The K D determined from equilibrium saturation binding studies was found to be 3.6 n M . However, the Hill coefficient was far below unity ( n H = 0.43), which suggests the presence of a second, lower affinity binding site. The presence of this binding component is strengthened by the displacement experiments performed with levorphanol and some other ligands. It is assumed that the lower affinity site has no opiate character. The rank order of potency of the applied ligands in competing reversibly with [3 H]Met-enkephalin-Arg6 -Phe7 binding reflects a κ2 - and/or δ-subtype specificity of the heptapeptide. Binding to a κ1 and/or μ site of opioid receptors is excluded, but the existence of a novel endogenous opiate receptor subtype for Met-enkephalin-Arg6 -Phe7 in frogs cannot be ruled out. The [3 H]Met-enkephalin-Arg6 -Phe7 binding was inhibited by both sodium ions and GppNHp, which suggests the opioid agonist character of the heptapeptide. 相似文献
100.