This domain is found associated with Pfam:PF01464. It is the N-terminal structural domain of MltC (Membrane-bound lytic murein transglycosylase C), one of the seven lytic transglycosylases found in the genome of the Gram-negative bacterium Escherichia coli. The role of the N-terminal domain is suggested to be important not as a mere structural extension of the active site beyond what is seen in other lytic transglycosylases but one that creates a peptide-binding site at position +2 [1].

1: Structure and cell wall cleavage by modular lytic transglycosylase MltC of Escherichia coli. Artola-Recolons C, Lee M, Bernardo-Garcia N, Blazquez B, Hesek D, Bartual SG, Mahasenan KV, Lastochkin E, Pi H, Boggess B, Meindl K, Uson I, Fisher JF, Mobashery S, Hermoso JA; ACS Chem Biol. 2014;9:2058-2066. PMID:24988330