pISSN 2288-6982
eISSN 2288-7105




BioDesign 2020; 8(3): 64-67

Published online September 30, 2020

© Korean Society for Structural Biology

Purification, crystallization, and preliminary analysis of the lysozyme-like enzyme SagA from Brucella abortus

Yongseong Hyun1, Jinsook Ahn1, Yeongjin Baek1, Yongbin Xu2,3,* and Nam-Chul Ha1,*

1Research Institute for Agriculture and Life Sciences, Center for Food and Bioconvergence, Center for Food Safety and Toxicology, Department of Agricultural Biotechnology, CALS, Seoul National University, Seoul 08826, Republic of Korea
2Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, Liaoning, China
3Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, Dalian 116600, China

Correspondence to:,

Received: July 10, 2020; Revised: August 6, 2020; Accepted: August 13, 2020


Brucella abortus is an intracellular bacterial pathogen that causes brucellosis in humans and livestock. The genome of B. abortus encodes the VirB type IV secretion system (T4SS), which is essential to its virulence. B. abortus produces and secretes effector proteins through the T4SS to survive in the intracellular environment and manipulate host immunity. The T4SS spans the peptidoglycan layer through vacancies in the peptidoglycan chain. Recently, secretion activator gene A (SagA) from B. abortus was identified as a lysozyme-like enzyme that creates holes in the peptidoglycan layer. In this study, SagA from B. abortus was overexpressed, purified, and crystallized. Crystal diffraction data were acquired at 2.0 Å resolution, a P213 space group with a unit cell parameter of 79.04 Å. We are currently exploring the crystal structure of SagA using the anomalous signal from selenomethionine-substituted crystals and an X-ray free-electron laser.