Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Investigation of the C-terminal domain of the bacterial DNA-(adenine N6)-methyltransferase CcrM

Maier, Johannes A H, Albu, Razvan F, Jurkowski, Tomasz P ORCID: and Jeltsch, Albert 2015. Investigation of the C-terminal domain of the bacterial DNA-(adenine N6)-methyltransferase CcrM. Biochimie 119 , 60—67. 10.1016/j.biochi.2015.10.011

Full text not available from this repository.


CcrM-related DNA-(adenine N6)-methyltransferases play very important roles in the biology of Caulobacter crescentus and other alpha-proteobacteria. These enzymes methylate GANTC sequences, but the molecular mechanism by which they recognize their target sequence is unknown. We carried out multiple sequence alignments and noticed that CcrM enzymes contain a conserved C-terminal domain (CTD) which is not present in other DNA-(adenine N6)-methyltransferases and we show here that deletion of this part abrogates catalytic activity and DNA binding of CcrM. A mutational study identified 7 conserved residues in the CTD (out of 13 tested), mutation of which led to a strong reduction in catalytic activity. All of these mutants showed altered DNA binding, but no change in AdoMet binding and secondary structure. Some mutants exhibited reduced DNA binding, but others showed an enhanced DNA binding. Moreover, we show that CcrM does not specifically bind to DNA containing GANTC sequences. Taken together, these findings suggest that the specific CcrM-DNA complex undergoes a conformational change, which is endergonic but essential for catalytic activity and this step is blocked by some of the mutations. Moreover, our data indicate that the CTD of CcrM is involved in DNA binding and recognition. This suggests that the CTD functions as target recognition domain of CcrM and, therefore, CcrM can be considered the first example of a δ-type DNA-(adenine N6)-methyltransferase identified so far.

Item Type: Article
Date Type: Published Online
Status: Published
Schools: Biosciences
Publisher: Elsevier
ISSN: 0300-9084
Date of Acceptance: 11 October 2015
Last Modified: 25 Oct 2022 13:08

Citation Data

Cited 6 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item