{PDOC00713}
{PS00922; TRANSGLYCOSYLASE}
{BEGIN}
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* Prokaryotic transglycosylases signature *
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Bacterial lytic transglycosylases degrade murein via cleavage of the beta-1,4-
glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine, with the
concomitant  formation  of  a  1,6-anhydrobond  in  the  muramic acid residue.
Escherichia coli  has  at  least  three different lytic transglycosylases: two
soluble isozymes  of 65 Kd and 35 Kd and a membrane-bound enzyme of 38 Kd. The
sequence of  the  65 Kd enzyme (gene slt) has been determined [1]. A domain of
about 90  residues  located  near  the  C-terminal section of slt was recently
shown [2] to be present in a number of other prokaryotic and phage proteins:

 - Membrane-bound lytic murein transglycosylase C (gene mltC).
 - Membrane-bound lytic murein transglycosylase D (gene mltD).
 - Membrane-bound lytic murein transglycosylase E (gene mltE).
 - Phage  T7  internal  protein  D  which  may be involved in the lysis of the
   bacterial cell wall during the release of phage progeny.
 - Phage PRD1 gene 7 protein.
 - Alteromonas strain M-1 possible tributyltin chloride resistance protein.
 - Escherichia coli hypothetical protein yfhD.

The domain  shared  by  these  proteins  could  be  involved  in     catalytic
activity. The  most  conserved part of this domain is its N-terminal extremity
which we used as a signature pattern. It contains two conserved serines and  a
glutamate which has been shown [3] to be involved in the catalytic mechanism.

-Consensus pattern: [LIVM]-x(3)-E-S-x(3)-[AP]-x(3)-S-x(5)-G-[LIVM]-[LIVMFYW]-
                    x-[LIVMFYW]-x(4)-[SAG]
                    [E is the active site residue]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.

-Expert(s) to contact by email:
           Dijkstra A.J.; arnoud_jan.dijkstra@roche.com

-Last update: November 1997 / Pattern and text revised.

[ 1] Engel H., Kazemier B., Keck W.
     "Murein-metabolizing enzymes from Escherichia coli: sequence analysis
     and controlled overexpression of the slt gene, which encodes the
     soluble lytic transglycosylase."
     J. Bacteriol. 173:6773-6782(1991).
     PubMed=1938883
[ 2] Koonin E.V., Rudd K.E.
     "A conserved domain in putative bacterial and bacteriophage
     transglycosylases."
     Trends Biochem. Sci. 19:106-107(1994).
     PubMed=8203016
[ 3] Thunnissen A.-M.W., Dijkstra A.J., Kalk K.H., Rozeboom H.J., Engel H.,
     Keck W., Dijkstra B.W.
     "Doughnut-shaped structure of a bacterial muramidase revealed by X-ray
     crystallography."
     Nature 367:750-753(1994).
     PubMed=8107871; DOI=10.1038/367750a0
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