Protein docking was conducted to investigate the interactions between NADH-dependent flavin reductase subunits (NFR1 and NFR2) and several functional partner proteins in Lactobacillus johnsonii. The main goal was to understand the binding dynamics and stability of these protein-protein complexes, as well as to identify potential functional associations. Docking results, visualized using PyMol, revealed strong and stable interactions for all tested complexes, evidenced by favorable energy scores and extensive surface contact areas, suggesting significant biological relevance for these interactions, which could influence key metabolic pathways in the organism.
Protein docking was simulated for NADH-dependent flavin reductase subunit 1 and 2 (combined complex named NFR) with nine different predicted functional partners. A summary of the findings is displayed in the table below.
Complex Name | 3D Model Representation | Description |
---|---|---|
NFR(nfr1 + nfr2) |
The complex between NFR1 (red) and NFR2 (blue) demonstrates a highly stable interaction with a cluster size of 141 and favorable energy scores of -474.6 (center) and -536.6 (lowest energy). | |
NFR+Oxidoreductase 1 |
The complex between the NFR complex (red) and Oxidoreductase 1 (blue) demonstrates a highly stable interaction with a cluster size of 98 and strong energy scores of -771.3 (center) and -820.3 (lowest energy). | |
NFR+Urocanate reductase |
The interaction between NFR complex (red) and Urocanate reductase (blue) shows a stable interaction with a cluster size of 103. The energy scores of -502.2 (center) and -556.2 (lowest energy). | |
NFR+Riboflavin biosynthesisprotein |
The interaction between NFR complex (red) and the Riboflavin biosynthesis (blue) protein is characterized by a cluster size of 82 and favorable energy scores of -574.3 (center) and -683.8 (lowest energy). | |
NFR+Flavocytochrome c |
The docking result between the NFR complex (red) and Flavocytochrome c (blue) shows a strong interaction interface. The cluster size of 86 and energy scores of -640.4 (center) and -784.8 (lowest energy). | |
NFR+Transposase |
The docking result between the NFR complex (red) and Transposase (blue) shows a strong interaction interface. The cluster size of 79 and energy scores of -690.3 (center) and -841.5 (lowest energy). | |
NFR+FAD : ProteinFMN transferase |
The docking result between the NFR complex (red) and FAD (FMN transferase in blue) shows a strong interaction interface. The cluster size of 73 and energy scores of -540.5 (center) and -707.5 (lowest energy). | |
NFR+Oxidoreductase 2 |
The NFR complex (red) and Oxidoreductase 2 (blue) complex exhibits a stable interaction with a cluster size of 85 and highly favorable energy scores of -788.2 (center) and -845.0 (lowest energy). | |
NFR+TetR familytranscriptional regulator |
The docking result between the NFR complex (red) and the TetR family transcriptional regulator (blue) shows a strong interaction interface. The cluster size of 56 and energy scores of -619.7 (center) and -738.4 (lowest energy). | |
NFR+Cell surface protein |
The docking result between the NFR complex (red) and the cell surface protein (blue) shows a strong interaction interface. The cluster size of 128 and energy scores of -514.8 (center) and -588.9 (lowest energy). |
A robust approach was employed to conduct the protein docking for functional partners of NFR (nfr1+nfr2). The workflow for how this was done is summarised in the flowchart below.
Our workflow for the Protein-Protein Docking can be broken down into 5 prominent steps.
Search for NFR1 (NADH-dependent flavin reductase subunit 1) and NFR2 (NADH-dependent flavin reductase subunit 1) proteins on uniprot.org:
Search for the predicted functional partners (nearby proteins) of NFR1 and NFR2 in Lactobacillus johnsonii:
Results: 9 proteins in total other than nfr1 and nfr2
Searching for Protein Sequences from UniProt and PDB Files from the AlphaFold Protein Structure Database.
Results compiled below:
Conduct Protein Docking using ClusPro:
Analysing the Docking Complexes in PyMol.
Code used to identify interactions in PyMol:
Example of visual representation seen in PyMol (NFR):
Analysis (for NFR):
Protein Colouring and Representation:
Nfr1 is represented in cyan.
Nfr2 is represented in magenta.
Interacting Residues (Red and Yellow): Specific residues at the interaction interface are highlighted in red and yellow. Red residues might indicate a key interaction site or a specific domain of interest, while yellow residues mark the interacting surfaces between the two proteins.
Interaction Interface:
Surface Contact: The visualisation shows a significant surface contact area between Nfr1 and Nfr2, indicating a strong interaction interface. The yellow regions suggest the specific areas where the two proteins are making contact.
Key Interaction Sites: The red-highlighted residues on the cyan protein (Nfr1) may represent critical points of interaction, such as binding sites or functionally important regions. These residues likely play a crucial role in stabilising the interaction.
Overall Binding Mode:
The interaction appears to involve a large surface area, which is typical for protein-protein interactions. This extensive contact area often contributes to the stability and specificity of the interaction.
Structural Complementarity:
The surface representations of Nfr1 and Nfr2 fit together well, indicating good structural complementarity. This suggests that the docking model is reasonable and biologically relevant.
Red Residue in-depth look:
Residue Representation: Sticks Representation: The residues involved in the interaction are shown in sticks representation, coloured in red, indicating they are important interaction sites.
Analysis similar to this example was conducted for each complex ad results were recorded in the summary table.
For detailed analysis of each complex, you may go through the pdf file attached below.