Crystal structure of human spermidine/spermine N1-acetyltransferase (hSSAT): the first structure of a new sequence family of transferase homologous superfamily.
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Acetyltransferases↗
Biomedical subjects
Yong-Qun Zhu
Publications and source records attributed to Yong-Qun Zhu.
Optimizing protein crystal growth through dynamic seeding.
A dynamic seeding method that is different from the conventional method of seeding drops that have been equilibrated is described. The method basically consists of two steps. Firstly, microseeding was used in association with adjustment of the seeding-drop components, including buffer, additive and concentrations of the precipitants and protein, in order to screen suitable seeding conditions under which microseeds are seeded into a new non-equilibrated drop as the dynamic macroseed drop for the following step. Secondly, after being equilibrated for various times against the reservoir solution, the macroseed drops were used to prepare a dilution series with which the qualified crystals could be harvested using macroseeding. Compared with a conventional seeding technique, this method is distinct with a dynamic situation of macroseed drops before macroseeding and a non-equilibrium serial seeding where all the seeds are seeded into new non-equilibrated drops and the micro/macroseeding are efficiently combined into a whole system. The method simplifies control of the number of microseeds because an excess of microseeds has little effect on the final result. The method also simplifies the manipulation of macroseeds by optimizing the equilibration time and the dilution multiple of the macroseed drops before macroseeding. This dynamic seeding technique has been used in the crystallization of novel protein CutCm, which has a fast crystal-growth rate, and proved that the method is useful for optimizing protein crystallization.
Bacterial Proteins↗
Crystal structure of the copper homeostasis protein (CutCm) from Shigella flexneri at 1.7 A resolution: the first structure of a new sequence family of TIM barrels.
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Amino Acid Sequence↗
Purification and preliminary crystallographic studies of CutC, a novel copper homeostasis protein from Shigella flexneri.
CutC is a novel copper homeostasis protein containing 248 amino acids. Here we report the cloning, expression, purification, crystallization and preliminary X-ray crystallographic studies of CutC from Shigella flexneri 2a. Purification of CutC and its selenomethionine (SeMet) derivate were done using immobilized metal ion affinity chromatography, size-exclusion and ion-exchange chromatography. The purified proteins were crystallized using the hanging drop vapor diffusion method. The diffraction data for the native and SeMet CutC, respectively, have been collected with resolution of 1.7 A and 2.1 A. They belong to the space group C2221 and similar cell dimension. The native protein crystals have cell parameters: a=75.3267, b=97.6718, c=132.6910.
Animals↗