Structure and Function of the Small MutS-Related Domain
Figure 2
Three-dimensional structures of Smr domains. (a) Solution structure of human N4BP2 Smr domain, a family 2 Smr domain (2d9i). (b) Crystal structure of T. thermophilus MutS2 Smr domain, a family 1 Smr domain (2zqe). (c) Crystal structure of the catalytic domain of E. coli RNase E (2c0b) [22]. (d) Crystal structure of the N-terminal domain of bovine DNase I (1dnk) [23]. (e) Amino acid sequence comparison between T. thermophilus MutS2 Smr domain and the catalytic domain of E. coli RNase E. The location of the secondary structure elements of the Smr domain is shown above the sequence. The residues essential for the catalytic activity of RNase E are shown by numbers below the sequence. The dimeric interface in the E. coli RNase E catalytic domain is underlined. (f) Amino acid sequence comparison between T. thermophilus MutS2 Smr domain and the N-terminal domain of bovine DNase I. The location of the secondary structure elements of the Smr domain is shown above the sequence. The residues essential for the DNA-binding ability are shown by numbers below the sequence. (g) Left: a salt bridge between Asp-669 and Arg-671 in the T. thermophilus Smr domain is represented with a broken line. Right: A hydrogen bond between Asp-303 and Asn-305 is also represented with a broken line.
