2B5A

C.BclI, Control Element of the BclI Restriction-Modification System

Summary for 2B5A

• Entry DOI: 10.2210/pdb2b5a/pdb
• Descriptor: C.BclI, ACETIC ACID (3 entities in total)
• Functional Keywords: helix-turn-helix motif, gene regulation
• Biological source: Bacillus caldolyticus
• Total number of polymer chains: 4
• Total formula weight: 35845.43

Authors

Sawaya, M.R.,Zhu, Z.,Mersha, F.,Chan, S.H.,Dabur, R.,Xu, S.Y.,Balendiran, G.K. (deposition date: 2005-09-28, release date: 2006-01-03, Last modification date: 2024-02-14)

Primary citation

Sawaya, M.R.,Zhu, Z.,Mersha, F.,Chan, S.H.,Dabur, R.,Xu, S.Y.,Balendiran, G.K.
Crystal Structure of the Restriction-Modification System Control Element C.BclI and Mapping of Its Binding Site.
Structure, 13:1837-1847, 2005

PubMed Abstract: Protection from DNA invasion is afforded by restriction-modification systems in many bacteria. The efficiency of protection depends crucially on the relative expression levels of restriction versus methytransferase genes. This regulation is provided by a controller protein, named C protein. Studies of the Bcll system in E. coli suggest that C.Bcll functions as a negative regulator for M.Bcll expression, implying that it plays a role in defense against foreign DNA during virus infection. C.Bcll binds (Kd = 14.3 nM) to a 2-fold symmetric C box DNA sequence that overlaps with the putative -35 promoter region upstream of the bcllM and bcllC genes. The C.Bcll fold comprises five alpha helices: two helices form a helix-turn-helix motif, and the remaining three helices form the extensive dimer interface. The C.Bcll-DNA model proposed suggests that DNA bending might play an important role in gene regulation, and that Glu27 and Asp31 in C.Bcll might function critically in the regulation.

PubMed: 16338412
DOI: 10.1016/j.str.2005.08.017

Experimental method

X-RAY DIFFRACTION (1.543 Å)