Crystal Structures of the Copper-Containing Amine Oxidase from Arthrobacter globiformis in the Holo and Apo Forms: Implications for the Biogenesis of Topaquinone
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- 作者：Matthew C. J. Wilce ; David M. Dooley ; Hans C. Freeman ; J. Mitchell Guss ; Hideyuki Matsunami ; William S. McIntire ; Christy E. Ruggiero ; Katsuyuki Tanizawa ; and Hiroshi Yamaguchi
- 刊名：Biochemistry
- 出版年：1997
- 出版时间：December 23, 1997
- 年：1997
- 卷：36
- 期：51
- 页码：16116 - 16133
- 全文大小：687K
- 年卷期：v.36,no.51(December 23, 1997)
- ISSN：1520-4995
文摘
The crystal structures of the copper enzymephenylethylamine oxidase from the Gram-positivebacterium Arthrobacter globiformis (AGAO) have beendetermined and refined for three forms of theenzyme: the holoenzyme in its active form (at 2.2 Å resolution), theholoenzyme in an inactive form (at2.8 Å resolution), and the apoenzyme (at 2.2 Å resolution). Theholoenzyme has a topaquinone (TPQ)cofactor formed from the apoenzyme by the post-translationalmodification of a tyrosine residue in thepresence of Cu2+. Significant differences betweenthe three forms of AGAO are limited to the activesite. The polypeptide fold is closely similar to those of theamine oxidases from Escherichia coli [Parsons,M. R., et al. (1995) Structure 3, 1171-1184] and peaseedlings [Kumar, V., et al. (1996) Structure4,943-955]. In the active form of holo-AGAO, the active-site Cuatom is coordinated by three His residuesand two water molecules in an approximately square-pyramidalarrangement. In the inactive form, theCu atom is coordinated by the same three His residues and by thephenolic oxygen of the TPQ, thegeometry being quasi-trigonal-pyramidal. There is evidence ofdisorder in the crystals of both forms ofholo-AGAO. As a result, only the position of the aromatic group ofthe TPQ cofactor, but not its orientationabout the C
chars/beta2.gif" BORDER=0 ALIGN="middle">-Cchars/gamma.gif" BORDER=0 > bond, is determinedunequivocally. In apo-AGAO, electron density consistent withanunmodified Tyr occurs at a position close to that of the TPQ in theinactive holo-AGAO. This observationhas implications for the biogenesis of TPQ. Two features whichhave not been described previously inamine oxidase structures are a channel from the molecular surface tothe active site and a solvent-filledcavity at the major interface between the two subunits of thedimer.
chars/beta2.gif" BORDER=0 ALIGN="middle">-Cchars/gamma.gif" BORDER=0 > bond, is determinedunequivocally. In apo-AGAO, electron density consistent withanunmodified Tyr occurs at a position close to that of the TPQ in theinactive holo-AGAO. This observationhas implications for the biogenesis of TPQ. Two features whichhave not been described previously inamine oxidase structures are a channel from the molecular surface tothe active site and a solvent-filledcavity at the major interface between the two subunits of thedimer.