Molecular cloning and sequencing of a pectinesterase gene from Pseudomonas solanacearum

Abstract

The predicted amino acid sequence showed significant homology to pectinesterases from Erwinia chrysanthemi and tomato. In cultures of E. coli clones up to 30% of total pectinesterase activity was transported into the medium. However, no significant pectinesterase activity could be detected in the periplasm.

Disulfide bridges in tomato pectinesterase: Variations from pectinesterases of other species; conservation of possible active site segments

“…This pattern is summarized in Figure 3. Other regions of similarity have been observed in previous comparisons of three of these structures (Spok et al, 1991). Notably, a central portion of the molecule, involving the 40-residue segment between the two disulfide bridges of the tomato enzyme, contains two of these conserved segments and two of the polar residues (2 Asp, cf.…”

“…Determination of the disulfide bridges in tomato pectinesterase, and the fact that primary structures of four highly divergent pectinesterases are now known, permits comparisons between pectinesterases in general. The four structures exhibit distant similarities (Hinton et al, 1990;MarkoviE & Jornvall, 1990;Spok et al, 1991 ; Fig. 2); however, the Cys residues differ in number and are not 0.…”

“…The top two lines show the two isoforms deduced from protein (Tl) and cDNA (T2) data of tomato pectinesterase (Lycopersicon esculenrum), the third line shows the enzyme analyzed from the nucleotide sequence of the Erwinia chrysanthemi pectinesterase gene (E), the fourth line the cDNA-deduced and peptideconfirmed structure of the enzyme from Aspergillus niger RH 5344 (A), and the bottom line the nucleotide sequence from the cloned pectinesterase gene of Pseudomonas solanacearum (P). Data from Plastow (1988), Ray et al (1988), Hinton et al (1990), Khanh et al (1990), Markovit and Jornvall (1990), and Spok et al (1991). Boxes indicate residue identities; dashes gaps.…”

“…Together, they control breakdown of the heteropolysaccharide pectin in plants (Rombouts & Pilnik, 1980) and regulate both physiological processes and pathogenic processes such as infection by phytopathogenic microorganisms (Collmer & Keen, 1986). To date, four different types of pectinesterase have been determined in primary structure, the pectinesterase from tomato (Ray et al, 1988;MarkoviE & Jornvall, 1990), Aspergillus niger (Khanh et al, 1990), Erwinia chrysanthemi (Plastow, 1988), and Pseudomonas solanacearum (Spok et al, 1991). These four enzymes are distantly related, exhibiting a low degree of sequence similarity, with residue identities at the 18-33% level (disregarding an elongated N-terminal overshooting end of the Pseudomonas enzyme).…”

The crystal structure of the outer membrane lipoprotein YbhC from Escherichia coli sheds new light on the phylogeny of carbohydrate esterase family 8

“…In earlier, less extensive phylogenetic work on CE8 proteins, this bacterial subclade had not been distinguished. 22,23 The first key branching point in the tree separates the CE8 members of the plant pathogenic bacteria Xanthomonas oryzae pv. oryzae (GenPept AAW75950) and Ralstonia solanacearum (GenPept AAS25984) from the clade containing YbhC and Erwinia chrysanthemi PmeB [ Fig.…”