Summary information and primary citation

PDB-id
7pnl
Class
DNA
Method
X-ray (1.83 Å)
Summary
Complex between monomolecular human telomeric g-quadruplex and a sulfonamide derivative of the natural alkaloid berberine
Reference
Nocentini A, Di Porzio A, Bonardi A, Bazzicalupi C, Petreni A, Biver T, Bua S, Marzano S, Amato J, Pagano B, Iaccarino N, De Tito S, Amente S, Supuran CT, Randazzo A, Gratteri P (2024): "Development of a multi-targeted chemotherapeutic approach based on G-quadruplex stabilisation and carbonic anhydrase inhibition." J Enzyme Inhib Med Chem, 39, 2366236. doi: 10.1080/14756366.2024.2366236.
Abstract
A novel class of compounds designed to hit two anti-tumour targets, G-quadruplex structures and human carbonic anhydrases (hCAs) IX and XII is proposed. The induction/stabilisation of G-quadruplex structures by small molecules has emerged as an anticancer strategy, disrupting telomere maintenance and reducing oncogene expression. hCAs IX and XII are well-established anti-tumour targets, upregulated in many hypoxic tumours and contributing to metastasis. The ligands reported feature a berberine G-quadruplex stabiliser scaffold connected to a moiety inhibiting hCAs IX and XII. <i>In vitro</i> experiments showed that our compounds selectively stabilise G-quadruplex structures and inhibit hCAs IX and XII. The crystal structure of a telomeric G-quadruplex in complex with one of these ligands was obtained, shedding light on the ligand/target interaction mode. The most promising ligands showed significant cytotoxicity against CA IX-positive HeLa cancer cells in hypoxia, and the ability to stabilise G-quadruplexes within tumour cells.
G4 notes
3 G-tetrads, 1 G4 helix, 1 G4 stem, UUUU, parallel, 4+0, 3(-P-P-P)

Cartoon-block schematics in six views (download the tarball)

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List of 3 G-tetrads

 1 glyco-bond=---- sugar=---- groove=---- planarity=0.055 type=planar O+ nts=4 GGGG A.DG2,A.DG8,A.DG14,A.DG20
 2 glyco-bond=---- sugar=---- groove=---- planarity=0.037 type=planar O+ nts=4 GGGG A.DG3,A.DG9,A.DG15,A.DG21
 3 glyco-bond=---- sugar=---- groove=---- planarity=0.153 type=planar O+ nts=4 GGGG A.DG4,A.DG10,A.DG16,A.DG22

List of 1 G4-helix

In DSSR, a G4-helix is defined by stacking interactions of G-tetrads, regardless of backbone connectivity, and may contain more than one G4-stem.

Helix#1, 3 G-tetrads, INTRA-molecular, with 1 stem
 1  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG2,A.DG8,A.DG14,A.DG20
 2  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG3,A.DG9,A.DG15,A.DG21
 3  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG4,A.DG10,A.DG16,A.DG22
  step#1  pm(>>,forward)  area=8.77  rise=3.31 twist=34.6
  step#2  pm(>>,forward)  area=13.42 rise=3.45 twist=25.8
  strand#1 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG2,A.DG3,A.DG4
  strand#2 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG8,A.DG9,A.DG10
  strand#3 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG14,A.DG15,A.DG16
  strand#4 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG20,A.DG21,A.DG22

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2 stacking diagrams
 1  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG2,A.DG8,A.DG14,A.DG20
2 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG3,A.DG9,A.DG15,A.DG21
step#1 pm(>>,forward) area=8.77 rise=3.31 twist=34.6

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 2  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG3,A.DG9,A.DG15,A.DG21
3 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG4,A.DG10,A.DG16,A.DG22
step#2 pm(>>,forward) area=13.42 rise=3.45 twist=25.8

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List of 1 G4-stem

In DSSR, a G4-stem is defined as a G4-helix with backbone connectivity. Bulges are also allowed along each of the four strands.

Stem#1, 3 G-tetrads, 3 loops, INTRA-molecular, UUUU, parallel, 4+0, 3(-P-P-P)
 1  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG2,A.DG8,A.DG14,A.DG20
 2  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG3,A.DG9,A.DG15,A.DG21
 3  glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG4,A.DG10,A.DG16,A.DG22
  step#1  pm(>>,forward)  area=8.77  rise=3.31 twist=34.6
  step#2  pm(>>,forward)  area=13.42 rise=3.45 twist=25.8
  strand#1  U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG2,A.DG3,A.DG4
  strand#2  U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG8,A.DG9,A.DG10
  strand#3  U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG14,A.DG15,A.DG16
  strand#4  U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG20,A.DG21,A.DG22
  loop#1 type=propeller strands=[#1,#2] nts=3 TTA A.DT5,A.DT6,A.DA7
  loop#2 type=propeller strands=[#2,#3] nts=3 TTA A.DT11,A.DT12,A.DA13
  loop#3 type=propeller strands=[#3,#4] nts=3 TTA A.DT17,A.DT18,A.DA19

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