A Meat-Derived Lactic Acid Bacteria, Lactobacillus plantarum IIA, Expresses a Functional Parvulin-Like Protein with Unique Structural Property

Abstract

The genome sequence of a Lactic Acid Bacterium (LAB) Lactobacillus plantarum IIA contains a single gene encoding a parvulin-like protein (Par-LpIIA). This protein belongs to Peptidyl Prolyl cis-trans Isomerase (PPIase) family proteins that catalyze a slow cis-trans isomerization of cis prolyl bond during protein folding. This study aims to provide molecular and biochemical evidences of the existence of Par-LpIIA in L. plantarum IIA and have an insight into its structural properties. The result showed that the gene encoding Par-LpIIA was successfully amplified using specific primers yielding a ~900 bp amplicon indicating that the gene indeed exists in its genomic DNA. BLAST analysis confirmed that the protein is a rotamase of parvulin-like protein. Further biochemical analysis demonstrated that cell lysate of L. plantarum IIA-1A5 exhibited remarkable PPIase activity towards peptide substrate and ability to accelerate the refolding of RNase T1, with the catalytic efficiency (kcat/KM) of 1.9 and 0.02 µM 1 s 1 , respectively. A specific inhibitor clearly inhibited the PPIase activity for parvulin-like protein with IC50 of 230 nM confirming that the protein encoded by Par-LpIIA gene is a parvulin-like protein and expressed in an active form. Further, the three-dimensional model of Par-LpIIA showed that this protein consists of two domains of a homolog WW domain and PPIase domain with a unique active site configuration compared to human Pin1. Altogether, we then proposed the possible roles of this protein for L. plantarum IIA.

Synthetic Gene-Based Heterologous Expression, Proteolytic, and Structural Characterization of Caseinolytic Protease of Lactobacillus plantarum IIA-1A5

“…This capacity is presumably because this strain secreted some proteases which can hydrolyze proteins in the muscles. Budiman et al (2021) indicated that the genome sequence of this strain harbors some functional genes for foldases and proteases. One protease gene encodes a caseinolytic protease (Clp) which is known to be an essential protease involved in cell division, stress responses, and pathogenicity of bacteria (Frees et al, 2014).…”