Conformational Changes in a Macrolide Antibiotic Binding Protein From Mycobacterium smegmatis Upon ADP Binding.
Zhang, Q., Liu, X., Liu, H., Zhang, B., Yang, H., Mi, K., Guddat, L.W., Rao, Z.(2021) Front Microbiol 12: 780954-780954
- PubMed: 34956144 
- DOI: https://doi.org/10.3389/fmicb.2021.780954
- Primary Citation of Related Structures:  
7CY2, 7CYR, 7CZ2 - PubMed Abstract: 
Rv3197 (MABP-1), a non-canonical ABC protein in Mycobacterium tuberculosis , has ATPase activity and confers inducible resistance to the macrolide family of antibiotics. Here we have shown that MSMEG_1954, the homolog of Rv3197 in M. smegmatis , has a similar function of conferring macrolide resistance. Crystal structures of apo-MSMEG_1954 (form1 and form 2) and MSMEG_1954 in complex with ADP have been determined. These three structures show that MSMEG_1954 has at least two different conformations we identify as closed state (MSMEG_1954-form 1) and open state (MSMEG_1954-form 2 and MSMEG_1954-ADP). Structural superimposition shows that the MSMEG_1954-form 2 and MSMEG_1954-ADP complex have similar conformation to that observed for MABP-1 and MABP-1-erythromicin complex structure. However, the antibiotic binding pocket in MSMEG_1954-form 1 is completely blocked by the N-terminal accessory domain. When bound by ADP, the N-terminal accessory domain undergoes conformational change, which results in the open of the antibiotic binding pocket. Because of the degradation of N terminal accessory domain in MSMSG_1954-form 2, it is likely to represent a transitional state between MSMEG_1954-form 1 and MSMEG_1954-ADP complex structure.
Organizational Affiliation: 
State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, China.