In silico structural analysis, classification, and functional annotation of uncharacterized protein from Corbicula fluminea
Main Article Content
Abstract
Heat shock protein 70 (HSP70) chaperones are essential molecular machines that facilitate the folding, assembly, and stabilization of numerous client proteins through ATP-dependent cycles of substrate binding and release. An uncharacterized protein sequence from Corbicula fluminea was initially annotated to contain domains with potential biotechnological relevance. This study employed in silico approaches using online tools for protein characterization including BLASTp, ExPASy, I-TASSER, EzMol, DeepLoc, SMART, and MEGA 12 software to determine its structural characteristics, classification, and potential functional role. Results revealed the presence of a conserved Pfam HSP70 domain (positions 6–612) and a Pfam MreB_Mbl domain (positions 116–384), along with a low-complexity region (positions 615–646). Subcellular localization prediction indicated a cytoplasmic distribution. Multiple sequence alignment and phylogenetic reconstruction using the Maximum Likelihood method showed that the HSP70 sequence from C. fluminea is closely related to known HSP70 sequences from related species, confirming its taxonomic placement within HSP70 protein family. Collectively, these results confirmed the protein as a member of HSP70 family and provide foundational insights into its structural and functional characteristics, contributing to the understanding of molecular chaperone biology in bivalves and informing future applications in biotechnology.
Article Details

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
References
Armenteros, J. J. A., Sønderby, C. K., Sønderby, S. K., Nielsen, H. and Winther, O. (2017). DeepLoc: Prediction of protein subcellular localization using deep learning. Bioinformatics, 33:3387-3395. https://doi.org/10.1093/bioinformatics/btx431
Bitacura, J. G. and Santos, M. D. (2022). In silico structural analysis, classification, and functional annotation of an uncharacterized protein from an aquatic fungus Lindgomyces ingoldianus. Genetics of Aquatic Organisms, 7. https://doi.org/10.4194/ga527
Chahouri, A., Yacoubi, B., Moukrim, A. and Banaoui, A. (2023). Bivalve molluscs as bioindicators of multiple stressors in the marine environment: Recent advances. Continental Shelf Research, 264:105056. https://doi.org/10.1016/j.csr.2023.105056
Chen, H., Zha, J., Liang, X., Bu, J., Wang, M. and Wang, Z. (2013). Sequencing and de novo assembly of the Asian clam (Corbicula fluminea) transcriptome using the Illumina GAIIx method. PLoS ONE, 8:e79516. https://doi.org/10.1371/journal.pone.0079516
Craig, E. A. (1989). Essential roles of 70 kDa heat inducible proteins. BioEssays, 11:48-52. https://doi.org/10.1002/bies.950110203
Falfushynska, H. I., Phan, T. and Sokolova, I. M. (2016). Long-term acclimation to different thermal regimes affects molecular responses to heat stress in a freshwater clam Corbicula fluminea. Scientific Reports, 6. https://doi.org/10.1038/srep39476
Gasteiger, E., Hoogland, C., Gattiker, A., Duvaud, S., Wilkins, M. R., Appel, R. D. and Bairoch, A. (2005). Protein identification and analysis tools on the ExPASY server. In J. M. Walker (Ed.), The proteomics protocols handbook. Humana Press, pp.571-607 https://doi.org/10.1385/1-59259-890-0:571
Hu, B., Liu, G., Zhao, K. and Zhang, G. (2024). Diversity of extracellular HSP70 in cancer: Advancing from a molecular biomarker to a novel therapeutic target. Frontiers in Oncology, 14:1388999. https://doi.org/10.3389/fonc.2024.1388999
Hu, C., Yang, J., Qi, Z., Wu, H., Wang, B., Zou, F., Mei, H., Liu, J., Wang, W. and Liu, Q. (2022). Heat Shock proteins: Biological functions, pathological roles, and therapeutic opportunities. MedComm, 3:e161. https://doi.org/10.1002/mco2.161
Jeyachandran, S., Chellapandian, H., Park, K. and Kwak, I. (2023). A review on the involvement of heat shock proteins (extrinsic chaperones) in response to stress conditions in aquatic organisms. Antioxidants, 12:1444. https://doi.org/10.3390/antiox12071444
Johnson, M., Zaretskaya, I., Raytselis, Y., Merezhuk, Y., McGinnis, S. and Madden, T. L. (2008). NCBI BLAST: A better web interface. Nucleic Acids Research, 36(Web Server), W5-W9. https://doi.org/10.1093/nar/gkn201
Kumar, S., Stecher, G., Suleski, M., Sanderford, M., Sharma, S. and Tamura, K. (2024). MEGA12: Molecular evolutionary genetic analysis version 12 for adaptive and green computing. Molecular Biology and Evolution, 41. https://doi.org/10.1093/molbev/msae263
Letunic, I., Khedkar, S. and Bork, P. (2020). SMART: Recent updates, new developments and status in 2020. Nucleic Acids Research, 49:D458-D460. https://doi.org/10.1093/nar/gkaa937
Mashjel, Z. and Al-Taher, Q. (2025). Molecular identification of the bivalves Corbicula fluminea and Sinanodonta woodiana in Thi-Qar Province, Iraq, using mitochondrial COX-I Gene Sequencing. Egyptian Journal of Aquatic Biology and Fisheries, 29:2347-2356. https://doi.org/10.21608/ejabf.2025.422893
Modrzejewska, M. and Zdanowska, O. (2024). The role of heat shock protein 70 (HSP70) in the pathogenesis of ocular diseases—Current literature review. Journal of Clinical Medicine, 13:3851. https://doi.org/10.3390/jcm13133851
Okawa, T., Kurita, Y., Kanno, K., Koyama, A. and Onikura, N. (2016). Molecular analysis of the distributions of the invasive Asian clam, Corbicula fluminea (O.F. Müller, 1774), and threatened native clam, C. leana Prime, 1867, on Kyushu Island, Japan. BioInvasions Records, 5:25-29. https://doi.org/10.3391/bir.2016.5.1.05
Reynolds, C. R., Islam, S. A. and Sternberg, M. J. (2018). EZMOL: A web server wizard for the rapid visualization and image production of protein and nucleic acid structures. Journal of Molecular Biology, 430:2244-2248. https://doi.org/10.1016/j.jmb.2018.01.013
Sidhu, A. (2023). Biological factors and its effect on HSP70 in Corbicula fluminea. American Journal of Biomedical Science & Research, 19:673-682. https://doi.org/10.34297/ajbsr.2023.19.002636
Sievers, F. and Higgins, D. G. (2017). Clustal Omega for making accurate alignments of many protein sequences. Protein Science, 27:135-145. https://doi.org/10.1002/pro.3290
Valenzuela-Castillo, A. V., Sanchez-Paz, A. S., Castro-Longoria, R. C., Lopez-Torres, M. L. and Grijalva-Chon, J. G. (2019). Hsp70 function and polymorphism, its implications for mollusk aquaculture: A review. Latin American Journal of Aquatic Research, 47:224-231. https://doi.org/10.3856/vol47-issue2-fulltext-2
Wentink, A., Rosenzweig, R., Kampinga, H. and Bukau, B. (2025). Mechanisms and regulation of the Hsp70 chaperone network. Nature Reviews Molecular Cell Biology, 27:110-128. https://doi.org/10.1038/s41580-025-00890-9
Xie, Y. (2017). Molecular characterization of the HSP70 and HSP90 genes in Asian clam (Corbicula fluminea) and their expression analysis during heavy metal exposure. Gene Reports, 7:18-24. https://doi.org/10.1016/j.genrep.2017.01.002
Xu, Y., Liang, J., He, G., Liu, X., Yang, K., Masanja, F., Deng, Y. and Zhao, L. (2022). Responses of pearl oysters to marine heatwaves as indicated by HSP70. Frontiers in Marine Science, 9. https://doi.org/10.3389/fmars.2022.847585
Yang, J. and Zhang, Y. (2015). I-TASSER server: New development for protein structure and function predictions. Nucleic Acids Research, 43:W174-W181. https://doi.org/10.1093/nar/gkv342
Zhang, T., Yin, J., Tang, S., Li, D., Gu, X., Zhang, S., Suo, W., Liu, X., Liu, Y., Jiang, Q., Zhao, M., Yin, Y. and Pan, J. (2021). Dissecting the chromosome-level genome of the Asian clam (Corbicula fluminea). Scientific Reports, 11. https://doi.org/10.1038/s41598-021-94545-2