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View Proteins belonging to: The Phosphotransferase System HPr (HPr) Family

8.A.8 The Phosphotransferase System HPr (HPr) Family

The HPr family consists of bacterial and archaeal proteins, all of which function as phosphoryl transfer proteins. They are energy-coupling constituents of the phosphotransferase system (PTS) (TC #4.A.1-4.A.7) which catalyzes sugar uptake via a group translocation mechanism. HPr proteins are not known to be homologous to any non-PTS proteins. The E. coli genome encodes five HPr paralogues. The functions of several of these proteins are known. They function in PTS-related regulatory capacities. 

Ruminiclostridium cellulolyticum has incomplete PTS components (Xu et al. 2023). Inactivation of the HPr homolog reduced rather than increased carbohydrate utilization. In addition to regulating transcriptional profiles, PTS associated CcpA (Catabolite Control Protein A) homologs diverged from previously described CcpA with varied metabolic relevance and distinct DNA binding motifs. The DNA binding of CcpA homologs is independent of HPr homologs, which are determined by structural changes at the interfaces of CcpA homologs. Thus, results support functional and structural diversification of PTS components in metabolic regulation and bring novel understanding of regulatory mechanisms of incomplete PTSs in cellulose-degrading clostridia (Xu et al. 2023).

View Proteins belonging to: The Phosphotransferase System HPr (HPr) Family

References associated with 8.A.8 family:

Araki N., Suzuki T., Miyauchi K., Kasai D., Masai E. and Fukuda M. (201). Identification and characterization of uptake systems for glucose and fructose in Rhodococcus jostii RHA1. J Mol Microbiol Biotechnol. 20(3):125-36. 21464575
Parche, S., R. Schmid, and F. Titgemeyer. (1999). The phosphotransferase system (PTS) of Streptomyces coelicolor identification and biochemical analysis of a histidine phosphocarrier protein HPr encoded by the gene ptsH. Eur J Biochem 265: 308-317. 10491187
Pickl A., Johnsen U. and Schonheit P. (2012). Fructose degradation in the haloarchaeon Haloferax volcanii involves a bacterial type phosphoenolpyruvate-dependent phosphotransferase system, fructose-1-phosphate kinase, and class II fructose-1,6-bisphosphate aldolase. J Bacteriol. 194(12):3088-97. 22493022
Postma, P.W., J.W. Lengeler and G.R. Jacobson (1993). Phosphoenolpyruvate:carbohydrate phosphotransferase systems of bacteria. Microbiol. Rev. 57: 543-594. 8246840
Reizer, J., C. Hoischen, A. Reizer, T.N. Pham and M.H. Saier, Jr. (1993). Sequence analyses and evolutionary relationships among the energy-coupling proteins Enzyme I and HPr of the bacterial phosphoenolpyruvate:sugar phosphotransferase system. Prot. Sci. 2: 506-521. 7686067
Titgemeyer, F., J. Walkenhorst, J. Reizer, M.H. Stuiver, X. Cui, and M.H. Saier, Jr. (1995). Identification and characterization of phosphoenolpyruvate:fructose phosphotransferase systems in three Streptomyces species. Microbiology 141(Pt1): 51-58. 7894719
Xu, T., X. Tao, H. He, M.L. Kempher, S. Zhang, X. Liu, J. Wang, D. Wang, D. Ning, C. Pan, H. Ge, N. Zhang, Y.X. He, and J. Zhou. (2023). Functional and structural diversification of incomplete phosphotransferase system in cellulose-degrading clostridia. ISME J 17: 823-835. 36899058