ID 62131
Author
Kouzai, Miho University of Tokushima
Kohaku, Yuko University of Tokushima
Sugiyama, Noriko University of Tokushima
Yamaguchi, Yasuaki University of Tokushima
Keywords
Inorganic pyrophosphatase
Site-directed mutagenesis
Submit interaction
Thermostability
Thermus thermophilus
Content Type
Departmental Bulletin Paper
Description
Inorganic pyrophosphatase (EC. 3.6.1.1) from Thermus thermophilus (Tth PPase) forms the thermostable
hexamer,and it was suggested from X-ray studies that its intersubunit interactions stabilize the whole molecule.
However,the contribution of Thr138 at the intertrimer interface to quatemary structure and thermostability was
unknown functionally. Therefore,we prepared four Thr138-substituted variants (T138A,V ,N ,and H) by
site-directed mutagenesis. Then,thermostabilities of the enzyme activity and the quatemary structure for T138V
and A were decreased relative to those of the wild type Tth PPase,whereas T138H and N variants remained
much hexamer contents and the enzyme activity than T138V and A. Therefore,we suggest that the polar group
in Thr138 of Tth PPase is more crucial than the methyl group for thermostability and quatemary structure,and it
may contribute to the formation of stable trimer-trimer interface.
Journal Title
徳島大学総合科学部自然科学研究 = Natural Science Research, The University of Tokushima
ISSN
09146385
NCID
AN10065859
Publisher
徳島大学総合科学部
Volume
22
Start Page
65
End Page
73
Sort Key
65
Published Date
2008-12-25
EDB ID
FullText File
language
eng
departments
Science and Technology