>gnl|CDD|100045 cd03354, LbH_SAT, Serine acetyltransferase (SAT): SAT catalyzes the CoA-dependent acetylation of the side chain hydroxyl group of L-serine to form O-acetylserine, as the first step of a two-step biosynthetic pathway in bacteria and plants leading to the formation of L-cysteine. This reaction represents a key metabolic point of regulation for the cysteine biosynthetic pathway due to its feedback inhibition by cysteine. The enzyme is a 175 kDa homohexamer, composed of a dimer of homotrimers. Each subunit contains an N-terminal alpha helical region and a C-terminal left-handed beta-helix (LbH) subdomain with 5 turns, each containing a hexapeptide repeat motif characteristic of the acyltransferase superfamily of enzymes. The trimer interface mainly involves the C-terminal LbH subdomain while the dimer (of trimers) interface is mediated by the N-terminal alpha helical subdomain.. Length = 101

 Score = 48.2 bits (116), Expect = 3e-06
 Identities = 32/106 (30%), Positives = 43/106 (40%), Gaps = 17/106 (16%)

Query: 137 GAYIGEGSMIDTWSTV--GSCAQIGKNVHISGGVGIGGVLEPIQTGPTIIEDNCFIGARS 194
           GA IG G  ID  + +  G  A IG N  I  GV +GG  +        I DN  IGA +
Sbjct: 8   GAKIGPGLFIDHGTGIVIGETAVIGDNCTIYQGVTLGGKGKGGGKRHPTIGDNVVIGAGA 67

Query: 195 EIVEGCIIREGSVLGMGVFIGKSTKIIDRNTGEITYGEVPSYSVVV 240
           +I+    I +   +G    + K                VP+ S VV
Sbjct: 68  KILGNITIGDNVKIGANAVVTKD---------------VPANSTVV 98