The prophage-encoded hyaluronate lyase has broad substrate specificity and is regulated by the N-terminal domain.
Streptococcus equi is the causative agent of the highly contagious disease "strangles" in equines and zoonotic meningitis in human. Spreading of infection in host tissues is thought to be facilitated by the bacterial gene encoded extracellular hyaluronate lyase (HL), which degrades hyaluronan (HA), chondroitin 6-sulfate, and dermatan sulfate of the extracellular matrix). The clinical strain S. equi 4047 however, lacks a functional extracellular HL. The prophages of S. equi and other streptococci encode intracellular HLs which are reported to partially degrade HA and do not cleave any other glycosaminoglycans. The phage HLs are thus thought to play a role limited to the penetration of streptococcal HA capsules, facilitating bacterial lysogenization and not in the bacterial pathogenesis. Here we systematically looked into the structure-function relationship of S. equi 4047 phage HL. Although HA is the preferred substrate, this HL has weak activity toward chondroitin 6-sulfate and dermatan sulfate and can completely degrade all of them. Even though the catalytic triple-stranded β-helix domain of phage HL is functionally independent, its catalytic efficiency and specificity is influenced by the N-terminal domain. The phage HL also interacts with human transmembrane glycoprotein CD44. The above results suggest that the streptococci can use phage HLs to degrade glycosaminoglycans of the extracellular matrix for spreading virulence factors and toxins while utilizing the disaccharides as a nutrient source for proliferation at the site of infection.
From the Molecular and Structural Biology Division.
Sudhir Kumar
SK
Singh
From the Molecular and Structural Biology Division.
Akhilendra Pratap
AP
Bharati
From the Molecular and Structural Biology Division.
Neha
N
Singh
Biochemistry Division.
Praveen
P
Pandey
Pharmacokinetics and Metabolism Division, and.
Pankaj
P
Joshi
Sophisticated Analytical Instrument Facility, Council of Scientific and Industrial Research-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, India, PIN 226 031 and.
Kavita
K
Singh
Sophisticated Analytical Instrument Facility, Council of Scientific and Industrial Research-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, India, PIN 226 031 and Academy of Scientific and Innovative Research, Chennai, India, PIN 600 113.
Kalyan
K
Mitra
Pharmacokinetics and Metabolism Division, and Academy of Scientific and Innovative Research, Chennai, India, PIN 600 113.
Jiaur R
JR
Gayen
Biochemistry Division, Academy of Scientific and Innovative Research, Chennai, India, PIN 600 113.
Jayanta
J
Sarkar
From the Molecular and Structural Biology Division, Academy of Scientific and Innovative Research, Chennai, India, PIN 600 113 sohail@cdri.res.in.
Md Sohail
MS
Akhtar
D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D020134:Catalytic Domain; D002809:Chondroitin Sulfates / Q000378:metabolism; D003871:Dermatan Sulfate / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005454:Fluorescence Polarization; D006025:Glycosaminoglycans / Q000378:metabolism; D045325:HCT116 Cells; D006736:Horses; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000378:metabolism; D007700:Kinetics; D018613:Microscopy, Confocal; D008958:Models, Molecular; D009154:Mutation; D011133:Polysaccharide-Lyases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D039002:Prophages / Q000201:enzymology* / Q000235:genetics; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D018502:Streptococcus equi / Q000821:virology*; D013379:Substrate Specificity; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D006025:Glycosaminoglycans; D018960:Hyaluronan Receptors; D014764:Viral Proteins; D003871:Dermatan Sulfate; D006820:Hyaluronic Acid; D002809:Chondroitin Sulfates; D011133:Polysaccharide-Lyases; C100002:hyaluronate lyase
Bacteriophage; Domain; Enzyme Catalysis; Glycosaminoglycan; Hyaluronate; Hyaluronic Acid; Streptococcus