Genes from Cellvibrio mixtus encoding β-1,3 endoglucanase

Two genes encoding β-1,3 glucanase activity were cloned from the gram-negative soil bacterium Cellvibrio mixtus. The two clones, designated cwd (cell wall degradation) and lam (laminarin degradation), had distinct endonuclease restriction patterns and encoded enzymes with distinct substrate specificities. The 3.7-kilobase cwd insert encoded an enzyme which degraded yeast cell walls as well as the soluble β-1,3 glucan laminarin and the insoluble β-1,3 glucans zymosan and pachyman. The 1.8-kilobase lam insert encoded an enzyme which degraded lamarin only. Both enzymes degraded laminarin in an endohydrolytic manner to yield laminarobiose, laminarotriose, and laminarotetraose as major end products. Radiolabeled translation products of the cwd and lam transcripts were identified