scholarly journals The structural basis of actinomycin D-binding induces nucleotide flipping out, a sharp bend and a left-handed twist in CGG triplet repeats

2013 ◽  
Vol 41 (13) ◽  
pp. 6782-6782 ◽  
Author(s):  
Y.-S. Lo ◽  
W.-H. Tseng ◽  
C.-Y. Chuang ◽  
M.-H. Hou
Keyword(s):  
Actinomycin D ◽  
Structural Basis ◽  
Triplet Repeats ◽  
Sharp Bend ◽  
Left Handed

scholarly journals The structural basis of actinomycin D–binding induces nucleotide flipping out, a sharp bend and a left-handed twist in CGG triplet repeats

2013 ◽  
Vol 41 (7) ◽  
pp. 4284-4294 ◽  
Author(s):  
Yu-Sheng Lo ◽  
Wen-Hsuan Tseng ◽  
Chien-Ying Chuang ◽  
Ming-Hon Hou
Keyword(s):  
Actinomycin D ◽  
Structural Basis ◽  
Triplet Repeats ◽  
Sharp Bend ◽  
Left Handed

Structural basis of the binding of Actinomycin D to CGG triplet repeats

2014 ◽  
Author(s):  
Yu-Sheng Lo ◽  
Wen-Hsuan Tseng ◽  
Chien-Ying Chuang ◽  
Ming-Hon Hou
Keyword(s):  
Actinomycin D ◽  
Structural Basis ◽  
Triplet Repeats

scholarly journals Structural basis for DNA unwinding at forked dsDNA by two coordinating Pif1 helicases

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nannan Su ◽  
Alicia K. Byrd ◽  
Sakshibeedu R. Bharath ◽  
Olivia Yang ◽  
Yu Jia ◽  
...  
Keyword(s):  
Base Pair ◽  
Genome Stability ◽  
Multiple Roles ◽  
Structural Basis ◽  
Dna Unwinding ◽  
Sharp Bend ◽  
Insight Into

AbstractPif1 plays multiple roles in maintaining genome stability and preferentially unwinds forked dsDNA, but the mechanism by which Pif1 unwinds forked dsDNA remains elusive. Here we report the structure of Bacteroides sp Pif1 (BaPif1) in complex with a symmetrical double forked dsDNA. Two interacting BaPif1 molecules are bound to each fork of the partially unwound dsDNA, and interact with the 5′ arm and 3′ ss/dsDNA respectively. Each of the two BaPif1 molecules is an active helicase and their interaction may regulate their helicase activities. The binding of BaPif1 to the 5′ arm causes a sharp bend in the 5′ ss/dsDNA junction, consequently breaking the first base-pair. BaPif1 bound to the 3′ ss/dsDNA junction impacts duplex unwinding by stabilizing the unpaired first base-pair and engaging the second base-pair poised for breaking. Our results provide an unprecedented insight into how two BaPif1 coordinate with each other to unwind the forked dsDNA.

scholarly journals The structure of the bacterial DNA segregation ATPase filament reveals the conformational plasticity of ParA upon DNA binding

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexandra V. Parker ◽  
Daniel Mann ◽  
Svetomir B. Tzokov ◽  
Ling C. Hwang ◽  
Julien R. C. Bergeron
Keyword(s):  
Dna Binding ◽  
Genetic Material ◽  
Structural Basis ◽  
Type I ◽  
Bacterial Cells ◽  
Adapter Protein ◽  
Bacterial Dna ◽  
Left Handed ◽  
Filament Assembly ◽  
Conformational Plasticity

AbstractThe efficient segregation of replicated genetic material is an essential step for cell division. Bacterial cells use several evolutionarily-distinct genome segregation systems, the most common of which is the type I Par system. It consists of an adapter protein, ParB, that binds to the DNA cargo via interaction with the parS DNA sequence; and an ATPase, ParA, that binds nonspecific DNA and mediates cargo transport. However, the molecular details of how this system functions are not well understood. Here, we report the cryo-EM structure of the Vibrio cholerae ParA2 filament bound to DNA, as well as the crystal structures of this protein in various nucleotide states. These structures show that ParA forms a left-handed filament on DNA, stabilized by nucleotide binding, and that ParA undergoes profound structural rearrangements upon DNA binding and filament assembly. Collectively, our data suggest the structural basis for ParA’s cooperative binding to DNA and the formation of high ParA density regions on the nucleoid.

Structural Basis for the Identification of an i-Motif Tetraplex Core with a Parallel-Duplex Junction as a Structural Motif in CCG Triplet Repeats

2014 ◽  
Vol 126 (40) ◽  
pp. 10858-10862 ◽  
Author(s):  
Yi-Wen Chen ◽  
Cyong-Ru Jhan ◽  
Stephen Neidle ◽  
Ming-Hon Hou
Keyword(s):  
Structural Motif ◽  
Structural Basis ◽  
Triplet Repeats

Chiral discrimination between left-handed and right-handed DNA supercoils by actinomycin D

1988 ◽  
Vol 37 (9) ◽  
pp. 1869-1870
Author(s):  
M. Savino ◽  
L. Leoni ◽  
S. Morosetti ◽  
C. Palermo ◽  
B. Sampaolese
Keyword(s):  
Actinomycin D ◽  
Chiral Discrimination ◽  
Left Handed

scholarly journals Structural basis for distinct operational modes and protease activation in AAA+ protease Lon

2020 ◽  
Vol 6 (21) ◽  
pp. eaba8404 ◽  
Author(s):  
Mia Shin ◽  
Cristina Puchades ◽  
Ananya Asmita ◽  
Neha Puri ◽  
Eric Adjei ◽  
...  
Keyword(s):  
Active Sites ◽  
Atp Hydrolysis ◽  
Structural Basis ◽  
Protein Substrates ◽  
Left Handed ◽  
Protease Activation ◽  
Active Protease ◽  
Mechanistic Basis ◽  
Aaa Protein ◽  
Operational Modes

Substrate-bound structures of AAA+ protein translocases reveal a conserved asymmetric spiral staircase architecture wherein a sequential ATP hydrolysis cycle drives hand-over-hand substrate translocation. However, this configuration is unlikely to represent the full conformational landscape of these enzymes, as biochemical studies suggest distinct conformational states depending on the presence or absence of substrate. Here, we used cryo–electron microscopy to determine structures of the Yersinia pestis Lon AAA+ protease in the absence and presence of substrate, uncovering the mechanistic basis for two distinct operational modes. In the absence of substrate, Lon adopts a left-handed, “open” spiral organization with autoinhibited proteolytic active sites. Upon the addition of substrate, Lon undergoes a reorganization to assemble an enzymatically active, right-handed “closed” conformer with active protease sites. These findings define the mechanistic principles underlying the operational plasticity required for processing diverse protein substrates.

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