TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
1.A.58.1.1









The Matrix protein BM2 (Pielak and Chou, 2010).  The solution structure for the channel domain of 33 aas is known (PDB# 2KIK) (Wang et al. 2009).  The channel transports H+ and K+ (Hyser and Estes 2015). Like M2, it is a tetrameric pore that acidifies the virion after endocytosis and it has a HxxxW motif (residues 19 - 23) in the single TMS responsible for proton selectivity and gating. This motif is within a 14 aa sequence with 35% identity and 86% similarity with M2 (1.A.19.1.1), both within the C-terminal part of the single TMS, suggesting homology. It also has a second histidine in a WxxxH motif involving the same W. The solvent-accessible His27 facilitates proton conduction of the channel by increasing the proton dissociation rates of His19 (Williams et al. 2017). The membrane environment is an important factor influencing the conformation and hydration of BM2 (Zhang et al. 2020).

 

Viruses
Orthomyxoviridae
BM2 influenza virus type B
(P03493)
1.A.58.1.2









Influenza Am2-Bm2 Chimeric Channel of 35 aas with 1 TMS. This hybrid sequence is RSNDSSDPLVVAASIIGILHFIAWTIGHLNQIKRG with the N-terminus derived from AM2 and the C-terminus derived from BM2 (PDB# 2KIK) (Pielak et al. 2011).

Viruses
Orthomyxoviridae
Chimeric AM2-BM2 35 aa peptide of A- and B-type Influenza viruses
1.A.58.1.3









Influenza virus B Matrix Protein 2, BM2 protein, of 109 aas and 1 N-terminal TMS.  83% identical and 92% similar to 1.A.58.1.1.

Viruses
Orthomyxoviridae
BM2 of Influenza B virus (B/Maryland)
1.A.58.1.4









M2 protein of 124 aas and 1 TMS.

Viruses
Negarnaviricota
M2 of Wuhan spiny eel influenza virus