Crystallographic and mutational analyses of cystathionine β‐synthase in the H2S‐synthetic gene cluster in Lactobacillus plantarum

• DOI: 10.1002/pro.3123
• Publication Date: 2017-01-27T08:52:28Z
• Authors: Yasuyuki Matoba; Tomoki Yoshida; Hisae Izuhara‐Kihara; Masafumi Noda; Masanori Sugiyama
• Keywords: Cystathionine gamma-lyase; Transsulfuration

Abstract Cystathionine β‐synthase (CBS) catalyzes the formation of l ‐cystathionine from ‐serine and ‐homocysteine. The resulting is decomposed into ‐cysteine, ammonia, α‐ketobutylic acid by cystathionine γ‐lyase (CGL). This reverse transsulfuration pathway, which catalyzed both enzymes, mainly occurs in eukaryotic cells. CBS CGL have recently been recognized as major physiological enzymes for generation hydrogen sulfide (H 2 S). In some bacteria, including plant‐derived lactic bacterium Lactobacillus plantarum , CBS‐ CGL‐encoding genes form a cluster their genomes. Inactivation these has reported to suppress H S production bacteria; interestingly, it shown that suppression increases susceptibility various antibiotics. present study, we characterized enzymatic properties L. CBS, whose amino sequence displays similarity with those O ‐acetyl‐ sulfhydrylase (OASS) ‐cysteine ( ‐OAS) S. shows ‐OAS‐ ‐cysteine‐dependent activities together OASS activity. Especially, presence ‐homocysteine, ‐cystathionine. high affinity toward first substrate tendency use ‐homocysteine second might be associated its ability generate Crystallographic mutational analyses indicate Ala70 Glu223 residues at binding pocket are important S‐generating