Suramin Targets the Conserved Ligand-Binding Pocket of Human Raf1 Kinase Inhibitory Protein.

Suramin was initially used to treat African sleeping sickness and has been clinically tested to treat human cancers and HIV infection in the recent years. However, the therapeutic index is low with numerous clinical side-effects, attributed to its diverse interactions with multiple biological macromolecules. Here, we report a novel binding target of suramin, human Raf1 kinase inhibitory protein (hRKIP), which is an important regulatory protein involved in the Ras/Raf1/MEK/ERK (MAPK) signal pathway.

Discovery and evaluation of new compounds targeting ribosomal protein S1 in antibiotic-resistant Mycobacterium Tuberculosis.

The emergence of antibiotic-resistant Mycobacterium Tuberculosis (Mtb) infections compels new treatment strategies, of which targeting trans-translation is promising. During the trans-translation process, the ribosomal protein S1 (RpsA) plays a key role, and the Ala438 mutant is related to pyrazinamide (PZA) resistance, which shows its effects after being hydrolysed to pyrazinoic acid (POA). In this study, based on the structure of the RpsA C-terminal domain (RpsA-CTD) and POA complex, new compounds were designed.

Lead compounds and key residues of ribosomal protein S1 in drug-resistant Mycobacterium tuberculosis.

Ribosomal protein S1 (RpsA) has been identified as a novel target of pyrazinoic acid (POA), which is the active form of pyrazinamide (PZA), in vivo. RpsA plays a crucial role in trans-translation, which is widespread in microbes. In our investigation, we first described the discovery of promising RpsA antagonists for drug-resistant mycobacterium (MtRpsAd438A) and M.

Anti-leprosy drug Clofazimine binds to human Raf1 kinase inhibitory protein and enhances ERK phosphorylation.

Human Raf1 kinase inhibitory protein (hRKIP) is an important modulator of the Ras/Raf1/MEK/ERK signaling pathway. Here, we demonstrated that anti-leprosy drug Clofazimine can bind to hRKIP with a significantly stronger affinity than the endogenous substrate phosphatidylethanolamine (PE) by using Biolayer interference technology. Moreover, we identified that residues P74, S75, K80, P111, P112, V177, and P178 play crucial roles in the binding of hRKIP to Clofazimine by using a combination of Nuclear Magnetic Resonance spectroscopy and molecular docking approach.

Structural basis for ribosome protein S1 interaction with RNA in trans-translation of Mycobacterium tuberculosis.

Ribosomal protein S1 (RpsA), the largest 30S protein in ribosome, plays a significant role in translation and trans-translation. In Mycobacterium tuberculosis, the C-terminus of RpsA is known as tuberculosis drug target of pyrazinoic acid, which inhibits the interaction between MtRpsA and tmRNA in trans-translation. However, the molecular mechanism underlying the interaction of MtRpsA with tmRNA remains unknown.