The NCBI CDD tool identifies the domain that appears in identical protein sequences. RPS-BLAST is used by CD-Search to compare a test sequence to position-specific rating datasets compiled from conserved domain (CD) alignments in the CD protein cluster. The CD search engine identified a conserved domain in the protein QBQ56721.1 as a viral matrix protein (matrix, accession no. pfam00661). Viral matrix proteins are structural proteins that connect the viral envelope and the virus core . The matrix protein play an important role in virus assembly and linking the viral envelope with the virus core . It's possible that they are found in Morbillivirus, Paramyxovirus, and Pneumovirus . A motif was also predicted by the Pfam software at locations 16-349 (Pfam ID: PF00661; Viral matrix protein; e value of 1:7 10146). Protein motifs are small regions of three-dimensional protein structure or amino acid sequence that are shared by multiple proteins . Motifs are distinct regions of protein structure that may or may not be defined by a distinct chemical or biological function . The CDD technique also confirmed the presence of viral matrix protein at the 17-348 position. The lone member of the superfamily cl02918 is the viral matrix protein (CDD no. pfam00661). A protein superfamily is a group of proteins made up of one or more protein families . The set of all superfamilies must be a partitioning of the set of all protein sequences or subsequences defined by the protein families relationship, and each superfamily must be closed under transitivity .The protein QBQ56721.1 (Figure ) was predicted to be closely related to the matrix superfamily by the SuperFamily tool (e value of 0).