1smn is a 2 chain structure with sequence from Serratia marcescens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The Serratia endonuclease is an extracellularly secreted enzyme capable of cleaving both single- and double-stranded forms of DNA and RNA. It is the first member of a large class of related and usually dimeric endonucleases for which a structure is known. Using X-ray crystallography, the structure of monomer of this enzyme was reported by us previously (Miller MD et al., 1994, Nature Struct Biol 1:461-468). We now confirm the dimeric nature of this enzyme through light-scattering experiments and identify the physiologic dimer interface through crystal packing analysis. This dimerization occurs through an isologous twofold interaction localized to the carboxy-terminal subdomain of the enzyme. The dimer is a prolate ellipsoid with dimensions 30 A x 35 A x 90 A. The dimer interface is flat and contains four salt links, several hydrogen bonds, and nonpolar interactions. Buried water is prominent in this interface and it includes an unusual "cubic" water cluster. The position of the two active sites in the dimer suggests that they can act independently in their cleavage of DNA, but have a geometrical advantage in attacking substrate relative to the monomer.
Identification of the Serratia endonuclease dimer: structural basis and implications for catalysis.,Miller MD, Krause KL Protein Sci. 1996 Jan;5(1):24-33. PMID:8771193[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Miller MD, Krause KL. Identification of the Serratia endonuclease dimer: structural basis and implications for catalysis. Protein Sci. 1996 Jan;5(1):24-33. PMID:8771193
