Design,construction, crystallization,and preliminary X-ray studies of a fine-tuning mutant (F133V) of module-substituted chimera hemoglobin |
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Authors: | Tsuyoshi Shirai Masahiro Fujikake Takashi Yamane Kenji Inaba Koichiro Ishimori Isao Morishima |
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Abstract: | A chimera βα-subunit of human hemoglobin was crystallized into a carbonmonoxy form. The protein was assembled by substituting the structural portion of a β-subunit of hemoglobin (M4 module of the subunit) for its counterpart in the α-subunit. In order to overcome the inherent instability in the crystallization of the chimera subunit, a site-directed mutagenesis (F133V) technique was employed based on a computer model. The crystal was used for an X-ray diffraction study yielding a data set with a resolution of 2.5 Å. The crystal belongs to the monoclinic space group P21, with cell dimensions of a = 62.9, b = 81.3, c = 55.1 Å, and β = 91.0°. These dimensions are similar to the crystallographic parameters of the native β-subunit tetramers in three different ligand states, one of which is a cyanide form that was also crystallized in this study. Proteins 32:263–267, 1998. © 1998 Wiley-Liss, Inc. |
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Keywords: | chimeric protein hemoglobin H protein engineering computer modeling molecular evolution |
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