Overexpression of penicillin V acylase from Streptomyces lavendulae and elucidation of its catalytic residues.

The pva gene from Streptomyces lavendulae ATCC 13664, encoding a novel penicillin V acylase (SlPVA), has been isolated and characterized. The gene encodes an inactive precursor protein containing a secretion signal peptide that is activated by two internal autoproteolytic cleavages that release a 25-amino-acid linker peptide and two large domains of 18.79 kDa (alpha-subunit) and 60.

Thoracoabdominal incision: a forgotten tool in the management of complex upper gastrointestinal complications.

Background: The gastroesophageal junction was commonly approached surgically through a thoracoabdominal incision. With the advent of improved retraction devices, this has been abandoned because the upper midline incision has provided adequate exposure with decreased morbidity. However, exposure of the gastroesophageal junction remains a challenge in the setting of surgical complications associated with repeat surgeries and abscess formation.