Type

Text

Type

Thesis

Advisor

Ojima, Iwao | Jakoncic, Jean | Tonge, Peter | French, Jarrod.

Date

2014-12-01

Keywords

Crystallization, FtsZ, Mtb, Protein Crystallography, Simulations, T9 loop | Chemistry

Department

Department of Chemistry.

Language

en_US

Source

This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.

Identifier

http://hdl.handle.net/11401/77117

Publisher

The Graduate School, Stony Brook University: Stony Brook, NY.

Format

application/pdf

Abstract

Filamenting temperature-sensitive mutant Z (FtsZ) from Mycobacterium tuberculosis (Mtb) is an essential bacterial cell division protein that polymerizes into a structure called the " Z-ring" . Here it has been targeted for drug discovery. Compounds that exhibit anti-tuberculosis activity have been synthesized and used in crystallization conditions. Four crystal structures of MtbFtsZ have been determined, of which two are similar to the published dimer (PDB 1RQ7) which exhibits lateral interactions; they belong to P65 space group and crystals diffracted to about 2.6Å. The other two structures had two trimers in the asymmetric unit. The crystals diffracted to approximately 3.5Å and the structures were refined to an Rcryst in the range of 0.24-0.28. These latter structures showed novel interactions including a hinge-opening mechanism in which Asn205, Asp207, and Asp210 from loop T7 of subunit A are within ~16Å of the nucleotide from subunit B. Additionally, subunit C from the trimer interacted with the central monomer B via a newly observed T9 loop interaction, where Glu231 from subunit B interacts with Gly18 and Gly107 from the nucleotide binding pocket of subunit C. Since all these residues are conserved it is plausible that this novel T9 interaction could play a role in the biological process in bacterial cell division. As a result, virtual docking was conducted on these two newly observed interactions (the T7 region and the T9 loop) with two small molecules of interest, SB-P17G-A20, which is a tri-substituted benzimidazole and SB-RA-5001, which is a taxane. Simulations revealed that one of the compounds interacts in the T9 region with a binding energy better than -7.5kcal/mol. | Filamenting temperature-sensitive mutant Z (FtsZ) from Mycobacterium tuberculosis (Mtb) is an essential bacterial cell division protein that polymerizes into a structure called the " Z-ring" . Here it has been targeted for drug discovery. Compounds that exhibit anti-tuberculosis activity have been synthesized and used in crystallization conditions. Four crystal structures of MtbFtsZ have been determined, of which two are similar to the published dimer (PDB 1RQ7) which exhibits lateral interactions; they belong to P65 space group and crystals diffracted to about 2.6Ã…. The other two structures had two trimers in the asymmetric unit. The crystals diffracted to approximately 3.5Ã… and the structures were refined to an Rcryst in the range of 0.24-0.28. These latter structures showed novel interactions including a hinge-opening mechanism in which Asn205, Asp207, and Asp210 from loop T7 of subunit A are within ~16Ã… of the nucleotide from subunit B. Additionally, subunit C from the trimer interacted with the central monomer B via a newly observed T9 loop interaction, where Glu231 from subunit B interacts with Gly18 and Gly107 from the nucleotide binding pocket of subunit C. Since all these residues are conserved it is plausible that this novel T9 interaction could play a role in the biological process in bacterial cell division. As a result, virtual docking was conducted on these two newly observed interactions (the T7 region and the T9 loop) with two small molecules of interest, SB-P17G-A20, which is a tri-substituted benzimidazole and SB-RA-5001, which is a taxane. Simulations revealed that one of the compounds interacts in the T9 region with a binding energy better than -7.5kcal/mol. | 62 pages

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.