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Structure and possible mechanism of the CcbJ methyltransferase from Streptomyces caelestis

SYSNO ASEP	0435764
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Structure and possible mechanism of the CcbJ methyltransferase from Streptomyces caelestis
Author(s)	Bauer, J. (SK) Ondrovičová, G. (SK) Najmanová, Lucie (MBU-M)_RID Pevala, V. (SK) Kameník, Zdeněk (MBU-M)_{RID, ORCID} Koštan, J. (SK) Janata, Jiří (MBU-M)_{RID, ORCID} Kutejová, Eva (MBU-M)_RID
Source Title	Acta Crystallographica Section D-Biological Crystallography. - : WILEY-BLACKWELL - ISSN 0907-4449 Roč. 70, APR 2014 (2014), s. 943-957
Number of pages	15 s.
Language	eng - English
Country	DK - Denmark
Keywords	CATECHOL-O-METHYLTRANSFERASE ; SN2-LIKE TRANSITION-STATE ; CRYSTAL-STRUCTURES
Subject RIV	CE - Biochemistry
R&D Projects	EE2.3.30.0003 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
	ED1.1.00/02.0109 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
Institutional support	MBU-M - RVO:61388971
UT WOS	000333756700004
DOI	10.1107/S139900471303397X
Annotation	The S-adenosyl-L-methionine (SAM)-dependent methyltransferase CcbJ from Streptomyces caelestis catalyzes one of the final steps in the biosynthesis of the antibiotic celesticetin, methylation of the N atom of its proline moiety, which greatly enhances the activity of the antibiotic. Since several celesticetin variants exist, this enzyme may be able to act on a variety of substrates. The structures of CcbJ determined by MAD phasing at 3.0 angstrom resolution, its native form at 2.7 angstrom resolution and its complex with S-adenosyl-l-homocysteine (SAH) at 2.9 angstrom resolution are reported here. Based on these structures, three point mutants, Y9F, Y17F and F117G, were prepared in order to study its behaviour as well as docking simulations of both CcbJ-SAM-substrate and CcbJ-SAH-product complexes. The structures show that CcbJ is a class I SAM-dependent methyltransferase with a wide active site, thereby suggesting that it may accommodate a number of different substrates. The mutation results show that the Y9F and F117G mutants are almost non-functional, while the Y17F mutant has almost half of the wild-type activity. In combination with the docking studies, these results suggest that Tyr9 and Phe117 are likely to help to position the substrate for the methyl-transfer reaction and that Tyr9 may also facilitate the reaction by removing an H+ ion. Tyr17, on the other hand, seems to operate by helping to stabilize the SAM cofactor.
Workplace	Institute of Microbiology
Contact	Eliška Spurná, eliska.spurna@biomed.cas.cz, Tel.: 241 062 231
Year of Publishing	2015

Number of the records: 1