Fusion of a bacterial cadherin-like domain and green fluorescent protein as a specific probe to study biofilm matrix formation in spp.

adhering proteins or 'Raps' are secreted proteins identified in a very restricted group of rhizobial strains, specifically those belonging to and . The distinctive feature of members of the Rap family is the presence of one or two cadherin-like domains or CHDLs that are also present in numerous extracellular bacterial and archaeal proteins and were proposed to confer carbohydrate binding ability. We have previously made an in-depth characterization of RapA2, a calcium-binding lectin, composed by two CHDLs, involved in biofilm matrix remodelling in bv.

Biodiversity of cultivable Burkholderia species in Argentinean soils under no-till agricultural practices.

No-tillage crop production has revolutionized the agriculture worldwide. In our country more than 30 Mha are currently cultivated under no-till schemes, stressing the importance of this management system for crop production. It is widely recognized that soil microbiota is altered under different soil managements.

A CHDL- (Cadherin-Like-) Lectin Participates in Assembly and Remodeling of the Biofilm Matrix.

In natural environments most bacteria live in multicellular structures called biofilms. These cell aggregates are enclosed in a self-produced polymeric extracellular matrix, which protects the cells, provides mechanical stability and mediates cellular cohesion and adhesion to surfaces. Although important advances were made in the identification of the genetic and extracellular factors required for biofilm formation, the mechanisms leading to biofilm matrix assembly, and the roles of extracellular proteins in these processes are still poorly understood.

Lipopolysaccharide O-chain core region required for cellular cohesion and compaction of in vitro and root biofilms developed by Rhizobium leguminosarum.

The formation of biofilms is an important survival strategy allowing rhizobia to live on soil particles and plant roots. Within the microcolonies of the biofilm developed by Rhizobium leguminosarum, rhizobial cells interact tightly through lateral and polar connections, forming organized and compact cell aggregates. These microcolonies are embedded in a biofilm matrix, whose main component is the acidic exopolysaccharide (EPS).

The BtaF trimeric autotransporter of Brucella suis is involved in attachment to various surfaces, resistance to serum and virulence.

The adhesion of bacterial pathogens to host cells is an event that determines infection, and ultimately invasion and intracellular multiplication. Several evidences have recently shown that this rule is also truth for the intracellular pathogen Brucella. Brucella suis displays the unipolar BmaC and BtaE adhesins, which belong to the monomeric and trimeric autotransporter (TA) families, respectively.

BtaE, an adhesin that belongs to the trimeric autotransporter family, is required for full virulence and defines a specific adhesive pole of Brucella suis.

Brucella is responsible for brucellosis, one of the most common zoonoses worldwide that causes important economic losses in several countries. Increasing evidence indicates that adhesion of Brucella spp. to host cells is an important step to establish infection.

RapA2 is a calcium-binding lectin composed of two highly conserved cadherin-like domains that specifically recognize Rhizobium leguminosarum acidic exopolysaccharides.

In silico analyses have revealed a conserved protein domain (CHDL) widely present in bacteria that has significant structural similarity to eukaryotic cadherins. A CHDL domain was shown to be present in RapA, a protein that is involved in autoaggregation of Rhizobium cells, biofilm formation, and adhesion to plant roots as shown by us and others. Structural similarity to cadherins suggested calcium-dependent oligomerization of CHDL domains as a mechanistic basis for RapA action.

Structure and mechanism of GumK, a membrane-associated glucuronosyltransferase.

Xanthomonas campestris GumK (beta-1,2-glucuronosyltransferase) is a 44-kDa membrane-associated protein that is involved in the biosynthesis of xanthan, an exopolysaccharide crucial for this bacterium's phytopathogenicity. Xanthan also has many important industrial applications. The GumK enzyme is the founding member of the glycosyltransferase family 70 of carbohydrate-active enzymes, which is composed of bacterial glycosyltransferases involved in exopolysaccharide synthesis.

The capsular polysaccharide biosynthesis of Streptococcus pneumoniae serotype 8: functional identification of the glycosyltransferase WciS (Cap8H).

CPS (capsular polysaccharide) is a major virulence factor in Streptococcus pneumoniae. Biosynthesis of CPS RU (repeat unit) proceeds by sequential transfer of sugar residues from the appropriate sugar donor to an activated lipid carrier by committed GTs (glycosyltransferases). While the nucleotide sequence of many cps loci is already known, the real substrate specificity of the hypothetical GTs, as well as the sequence of sugar addition is unclear.

Functional characterization of GumK, a membrane-associated beta-glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis.

Xanthomonas campestris is a Gram-negative bacterium that produces an exopolysaccharide known as xanthan gum. Xanthan is involved in a variety of biological functions, including pathogenesis, and is widely used in the industry as thickener and viscosifier. Although the genetics and biosynthetic process of xanthan are well documented, the enzymatic components have not been examined and no data on glycosyltransferases have been reported.