TY  - JOUR
AU  - Das, Uddipan
AU  - Pogenberg, Vivian
AU  - Subhramanyam, Udaya Kumar Tiruttani
AU  - Wilmanns, Matthias
AU  - Gourinath, Samudrala
AU  - Srinivasan, Alagiri
TI  - Crystal Structure of the VapBC-15 Complex from Mycobacterium Tuberculosis Reveals a Two-Metal Ion dependent PIN-Domain Ribonuclease and a Variable Mode of Toxin-Antitoxin Assemblypetea
JO  - Journal of structural biology
VL  - 188
IS  - 3
SN  - 1047-8477
CY  - San Diego, Calif.
PB  - Elsevier
M1  - PUBDB-2015-01365
SP  - 249 - 258
PY  - 2014
N1  - (c) Elsevier Inc. Post referee full text in progress. Embargo for full text 1 year from 22. Oct. 2014.
AB  - Although PIN (PilT N-terminal)-domain proteins are known to have ribonuclease activity, their specific mechanism of action remains unknown. VapCs form a family of ribonucleases that possess a PIN-domain assembly and are known as toxins. The activities of VapCs are impaired by VapB antitoxins. Here we present the crystal structure of the VapBC-15 toxin–antitoxin complex from Mycobacterium tuberculosis determined to 2.1 Å resolution. The VapB-15 and VapC-15 components assemble into one heterotetramer (VapB<sub>2</sub>C<sub>2</sub>) and two heterotrimers (VapBC<sub>2</sub>) in each asymmetric unit of the crystal. The active site of VapC-15 toxin consists of a cluster of acidic amino acid residues and two divalent metal ions, forming a well organised ribonuclease active site. The distribution of the catalytic-site residues of the VapC-15 toxin is similar to that of T4 RNase H and of Methanococcus jannaschii FEN-1, providing strong evidence that these three proteins share a similar mechanism of activity. The presence of both VapB<sub>2</sub>C<sub>2</sub> and VapBC<sub>2</sub> emphasizes the fact that the same antitoxin can bind the toxin in 1:1 and 1:2 ratios. The crystal structure determination of the VapBC-15 complex reveals for the first time a PIN-domain ribonuclease protein that shows two metal ions at the active site and a variable mode of toxin–antitoxin assembly. The structure further shows that VapB-15 antitoxin binds to the same groove meant for the binding of putative substrate (RNA), resulting in the inhibition of VapC-15’s toxicity.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000346229500007
C6  - pmid:25450593
DO  - DOI:10.1016/j.jsb.2014.10.002
UR  - https://bib-pubdb1.desy.de/record/207477
ER  -