Crystallization and preliminary X‐ray analysis of human MTH1 with a homogeneous N‐terminus. Issue 1 (8th January 2013)

• Record Type: Journal Article
• Authors: Koga, Yukari; Inazato, Miyuki; Nakamura, Teruya; Hashikawa, Chie; Chirifu, Mami; Michi, Asuka; Yamashita, Taku; Toma, Sachiko; Kuniyasu, Akihiko; Ikemizu, Shinji; Nakabeppu, Yusaku; Yamagata, Yuriko
• Is Part Of: Acta crystallographica. Volume 69:Issue 1(2013:Jan.)
• Page Start: 45
• Page End: 48
• Publication Date: 2013-01-08
• Subjects: Crystallography -- Periodicals; Crystals -- Periodicals; 548
• DOI: 10.1107/S1744309112048002
• Languages: English
• ISSNs: 1744-3091

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Human MTH1 (hMTH1) is an enzyme that hydrolyses several oxidized purine nucleoside triphosphates to their corresponding nucleoside monophosphates. Crystallographic studies have shown that the accurate mode of interaction between 8‐oxoguanine and hMTH1 cannot be understood without determining the positions of the H atoms, as can be observed in neutron and/or ultrahigh‐resolution X‐ray diffraction studies. The hMTH1 protein prepared in the original expression system from <italic>Escherichia coli</italic> did not appear to be suitable for obtaining high‐quality crystals because the hMTH1 protein had heterogeneous N‐termini of Met1 and Gly2 that resulted from N‐terminal Met excision by methionine aminopeptidase from the <italic>E. coli</italic> host. To obtain homogeneous hMTH1, the Gly at the second position was replaced by Lys. As a result, mutant hMTH1 protein [hMTH1(G2K)] with a homogeneous N‐terminus could be prepared and high‐quality crystals which diffracted to near 1.1 Å resolution using synchrotron radiation were produced. The new crystals belonged to space group <italic>P</italic>2₁2₁2₁, with unit‐cell parameters <italic>a</italic> = 46.36, <italic>b</italic> = 47.58, <italic>c</italic> = 123.89 Å.</p> </abstract>