BS1

Another study done on plants gives a different dimension to GDSL esterase activity . In this study, a forward genetic screen reveals a brittle leaf sheath 1 (bs1) mutant that is characterized by brittle leaf sheaths. Further genomic investigation, reveals that the BS1 gene codes for a GDSL esterase that removes acetyl moieties from xylan backbones. Because xylan is a major component of secondary cell walls, secondary cell wall architecture is compromised in bs1 mutants. This suggests that this GDSL esterase allows proper secondary wall patterning to occur. BS1 is ubiquitously expressed in plants but more in vascular tissues. Subcellular examination revealed localization in the Golgi apparatus. This is interesting because prior to this discovery, no GDSL esterase/lipase had been discovered to have polysaccharide esterase activity.