However,the genome of Chlamydiae includes a complete set of genes for the synthesis of murein. They are also susceptible to antibiotics such as -lact and D-cyclo which inhibit murein synthesis. It is not known how these biosynthetic genes are repressed or how the antibiotics inhibit growth. These organisms have cysteine-rich proteins in their outer membrane. Disulfide bonds in the protein render the cells resistant to osmotic pressure.
the phylum planc is one of the major divisions of the domain bacteria and is phylogenetically deep -rooted. These bacteria lack murein in their cell wall,which mainly comprises protein,and is probably an S-layer.
the archaeal cell wall is different from the bacterial cell wall. The main components of the archaeal cell wall include pseudomurein,sulfonatet polysaccharide and glycoprotein.