Natalie Osorio
Stony Brook University
Biophysical Investigations Into the Structure and Function of Pa and Bt Nitric oxide sensing Proteins
A biofilm is an organized community of microorganisms that attaches to a surface and is protected from environmental stressors by forming an extracellular polymeric substance. Biofilms are a public health hazard because they contribute to antimicrobial resistance and cause infections in hospitalized patients. According to Barraud et al. (2006), Nitric oxide (NO) is an important signaling molecule in pathogenic bacteria and has the potential to disperse biofilms. The nitric oxide-sensing protein (NosP) has been studied in several gram-negative bacteria, including Pseudomonas aeruginosa (Pa), Vibrio cholerae (Vc), and Burkholderia thailandensis (Bt). Specifically, Bt will be used in this study, which is a causative agent of melioidosis. Bt is also a model organism of Burkholderia pseudomallei (Bp), a BSL-3 pathogen, in which it shares a 42% identity. According to Heckler et al. (2020), studies on Vibrio cholerae have shown that NosP can also sense heme, and in 2021, Fu et al. showed that BtNosP functions as a heme-responsive protein. The AlphaFold-predicted structure of BtNosP suggests that tyrosine 285 (Y285) is located near the heme-binding pocket, indicating a potential role in direct heme interaction or stabilization (Jumper et al., 2021). In a related homolog, PaNosP molecular dynamics simulations revealed that tyrosine 270 (Y270) influences global heme dynamics. In BtNosP, the corresponding residue is Y269, prompting interest in whether this tyrosine plays a similar functional role. Overall, the goal of this project is to elucidate the functional contributions of Y285 and Y269 to heme binding and dynamics in BtNosP, respectively.
A biofilm is an organized community of microorganisms that attaches to a surface and is protected from environmental stressors by forming an extracellular polymeric substance. Biofilms are a public health hazard because they contribute to antimicrobial resistance and cause infections in hospitalized patients. According to Barraud et al. (2006), Nitric oxide (NO) is an important signaling molecule in pathogenic bacteria and has the potential to disperse biofilms. The nitric oxide-sensing protein (NosP) has been studied in several gram-negative bacteria, including Pseudomonas aeruginosa (Pa), Vibrio cholerae (Vc), and Burkholderia thailandensis (Bt). Specifically, Bt will be used in this study, which is a causative agent of melioidosis. Bt is also a model organism of Burkholderia pseudomallei (Bp), a BSL-3 pathogen, in which it shares a 42% identity. According to Heckler et al. (2020), studies on Vibrio cholerae have shown that NosP can also sense heme, and in 2021, Fu et al. showed that BtNosP functions as a heme-responsive protein. The AlphaFold-predicted structure of BtNosP suggests that tyrosine 285 (Y285) is located near the heme-binding pocket, indicating a potential role in direct heme interaction or stabilization (Jumper et al., 2021). In a related homolog, PaNosP molecular dynamics simulations revealed that tyrosine 270 (Y270) influences global heme dynamics. In BtNosP, the corresponding residue is Y269, prompting interest in whether this tyrosine plays a similar functional role. Overall, the goal of this project is to elucidate the functional contributions of Y285 and Y269 to heme binding and dynamics in BtNosP, respectively.
