Crystal Structure of Mycobacterium tuberculosis Elongation Factor G1

Xiaopan Gao,Wei Wang,Kaixiang Zhu,Xia Yu,Pu Han,Bo Qin,Meitian Wang,Justyna Aleksandra Wojdyla,Sheng Cui

doi:10.3389/fmolb.2021.667638

Abstract

Mycobacterium tuberculosis (Mtb) caused an estimated 10 million cases of tuberculosis and 1.2 million deaths in 2019 globally. The increasing emergence of multidrug-resistant and extensively drug-resistant Mtb is becoming a public health threat worldwide and makes the identification of anti-Mtb drug targets urgent. Elongation factor G (EF-G) is involved in tRNA translocation on ribosomes during protein translation. Therefore, EF-G is a major focus of structural analysis and a valuable drug target of antibiotics. However, the crystal structure of Mtb EF-G1 is not yet available, and this has limited the design of inhibitors. Here, we report the crystal structure of Mtb EF-G1 in complex with GDP. The unique crystal form of the Mtb EF-G1-GDP complex provides an excellent platform for fragment-based screening using a crystallographic approach. Our findings provide a structure-based explanation for GDP recognition, and facilitate the identification of EF-G1 inhibitors with potential interest in the context of drug discovery.

Highlights

Mycobacterium tuberculosis (Mtb), one of the deadliest bacterial pathogens causing tuberculosis, is still threatening humanity in the 21st century
A single clone was randomly picked from a LB plate and inoculated in LB medium at 37°C and protein expression was induced by the addition of 0.5 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) when the culture OD600 reached approximately 1.0. the bacterial culture was cooled to 22°C in incubator and continued with shaking speed of 180rpm overnight after induction
To investigate the GDP binding ability of Mtb EF-G1, we first carried out isothermal titration calorimetry (ITC) experiments to verify the GDP affinity of Mtb EF-G1.The results showed that Mtb EF-G1 binds GDP with an apparent dissociation constant (Kd) of 11.5 ± 0.3 μM (Supplementary Figure S1C)

Summary

INTRODUCTION

Mycobacterium tuberculosis (Mtb), one of the deadliest bacterial pathogens causing tuberculosis, is still threatening humanity in the 21st century. The emergence of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) undermine conventional treatments. For this reason, it is urgent to identify novel inhibitor targets and develop new and effective Mtb drugs. Argyins exhibiting antibacterial activity against Gram-negative pathogens target EF-G via a novel mechanism (Nyfeler et al, 2012; Jones et al, 2017). The structure determination of Mtb EF-G1 represents the key step for the structure-based design of inhibitors, in future activities, which will be investigated to assess their potential in the context of anti-TB drug development. The Mtb EF-G1CGDP crystal structure presents a complete description of GDP recognition and provides solid structural insight into the design and development inhibitors targeting Mtb EF-G1

MATERIALS AND METHODS

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT