scholarly journals Similar but Still Different: Which Amino Acid Residues Are Responsible for Varying Activities in Type‐III Copper Enzymes?

ChemBioChem ◽  
2020 ◽  
Author(s):  
Ioannis Kampatsikas ◽  
Annette Rompel
Keyword(s):  
Amino Acid ◽  
Amino Acid Residues ◽  
Copper Enzymes ◽  
Type Iii

scholarly journals Identification of COL7A1 Alternative Splicing Inserting 9 Amino Acid Residues Into the Fibronectin Type III Linker Domain

2003 ◽  
Vol 120 (6) ◽  
pp. 942-948 ◽  
Author(s):  
Daisuke Sawamura ◽  
Maki Goto ◽  
Kana Yasukawa ◽  
Masashi Akiyama ◽  
Hiroshi Shimizu ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Amino Acid ◽  
Amino Acid Residues ◽  
Type Iii ◽  
Fibronectin Type Iii ◽  
Linker Domain ◽  
Fibronectin Type

scholarly journals Alteration of reaction and substrate specificity of a bacterial type III polyketide synthase by site-directed mutagenesis

2002 ◽  
Vol 367 (3) ◽  
pp. 781-789 ◽  
Author(s):  
Nobutaka FUNA ◽  
Yasuo OHNISHI ◽  
Yutaka EBIZUKA ◽  
Sueharu HORINOUCHI
Keyword(s):  
Amino Acid ◽  
Active Site ◽  
Polyketide Synthase ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Type Iii Polyketide Synthase ◽  
Melanin Biosynthesis ◽  
Type Iii ◽  
Malonyl Coa

RppA, which belongs to the type III polyketide synthase family, catalyses the synthesis of 1,3,6,8-tetrahydroxynaphthalene (THN), which is the key intermediate of melanin biosynthesis in the bacterium Streptomyces griseus. The reaction of THN synthesis catalysed by RppA is unique in the type III polyketide synthase family, in that it selects malonyl-CoA as a starter substrate. The Cys-His-Asn catalytic triad is also present in RppA, as in plant chalcone synthases, as revealed by analyses of active-site mutants having amino acid replacements at Cys138, His270 and Asn303 of RppA. Site-directed mutagenesis of the amino acid residues that are likely to form the active-site cavity revealed that the aromatic ring of Tyr224 is essential for RppA to select malonyl-CoA as a starter substrate, since substitution of Tyr224 by amino acids other than Phe and Trp abolished the ability of RppA to accept malonyl-CoA as a starter, whereas the mutant enzymes Y224F and Y224W were capable of synthesizing THN via the malonyl-CoA-primed reaction. Of the site-directed mutants generated, A305I was found to produce only a triketide pyrone from hexanoyl-CoA as starter substrate, although wild-type RppA synthesizes tetraketide and triketide pyrones in the hexanoyl-CoA-primed reaction. The kinetic parameters of Ala305 mutants and identification of their products showed that the substitution of Ala305 by bulky amino acid residues restricted the number of elongations of the growing polyketide chain. Both Tyr224 (important for starter substrate selection) and Ala305 (important for intermediate elongation) were found to be conserved in three other RppAs from Streptomyces antibioticus and Streptomyces lividans.

scholarly journals Comparison of the amino acid sequences of the variable domains of two homogeneous rabbit antibodies to type III pneumococcal polysaccharide

1975 ◽  
Vol 147 (2) ◽  
pp. 235-247 ◽  
Author(s):  
J C Jaton
Keyword(s):  
Amino Acid ◽  
Complete Sequence ◽  
Amino Acid Sequences ◽  
Light Chains ◽  
Amino Acid Residues ◽  
Rabbit Antibody ◽  
Variable Regions ◽  
Type Iii ◽  
Variable Domains ◽  
V Region

The amino acid sequences of the V (variable) regions of the H (heavy) and L (light) chains derived from rabbit antibody K-25, specific for type III pneumococci, were determined; this is the second homogeneous rabbit antibody besides antibody BS-5 whose complete sequence of the V domain has been established (Jaton, 1974d). The V regions of L chains BS-5 and K-25 (both of allotype b4) differ from each other by 19 amino acid residues; 11 of these 19 substitutions are located within the three hypervariable sections of the V region. On the basis of seven amino acid differences within the N-terminal 28 positions, it is suggested that L chain K-25 belongs to a different subgroup of rabbit K chains and L chain BS-5. H chain K-25 (allotype a2) differs from another H chain of the same allotype by one amino acid substitution within the N-terminal 70 positions in addition to interchanges occurring in the first two hypervariable sections. H chain K-25 was compared with H chain BS-5 (allotype a1) and with the known V-region rabbit sequences. Allotype-related differences between a1, a2 and a3 chains appear to occur within the N-terminal 16 positions and possibly in scattered positions throughout the V-region. In the hypervariable positions, variability between the two antibodies is remarkably more pronounced within the third hypervariable section of both H and L chains than within the first two.

scholarly journals Genetic Analysis of the Salmonella enterica Type III Secretion-Associated ATPase InvC Defines Discrete Functional Domains

2004 ◽  
Vol 186 (8) ◽  
pp. 2402-2412 ◽  
Author(s):  
Yukihiro Akeda ◽  
Jorge E. Galán
Keyword(s):  
Amino Acid ◽  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Amino Acid Residues ◽  
Secretion Systems ◽  
Type Iii ◽  
Type Iii Secretion Systems ◽  
Discrete Domains

ABSTRACT An essential component of all type III secretion systems is a highly conserved ATPase that shares significant amino acid sequence similarity to the β subunit of the F0F1 ATPases and is thought to provide the energy for the secretion process. We have performed a genetic and functional analysis of InvC, the ATPase associated with the Salmonella enterica type III secretion system encoded within its pathogenicity island 1. Through a mutagenesis analysis, we have identified amino acid residues that are essential for specific activities of InvC, such as nucleotide hydrolysis and membrane binding. This has allowed us to define discrete domains of InvC that are specifically associated with different essential activities of this protein.

scholarly journals Comparison of the amino acid sequences of the variable regions of light chains derived from two homogeneous rabbit anti-pneumococcal antibodies

1974 ◽  
Vol 141 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Jean-Claude Jaton
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Light Chain ◽  
Amino Acid Sequences ◽  
Basic Sequence ◽  
Light Chains ◽  
Amino Acid Residues ◽  
Rabbit Antibody ◽  
Variable Regions ◽  
Type Iii

The amino acid sequence of the N-terminal 139 residues of the L (light) chain derived from a homogeneous rabbit antibody to type III pneumococci was determined. This L chain, designated BS-5, exhibits a greater degree of homology with the basic sequence of human κ chains of subgroup I (72%) than with subgroups II and III. L-chain BS-5 differs from another L chain (BS-1), also derived from an antibody to type III pneumococci (Jaton, 1974), by eight amino acid residues, even though the chains are identical within the N-terminal 30 residues. Six of these eight substitutions are located within the three hypervariable sections of the variable half: Asn/Ser in position 31, Glu/Ala in position 55, Asx/Thr, Thr/Gly, Thr/Gly and Val/Tyr in positions 92, 94, 96 and 97 respectively. The two anti-pneumococcal L chains BS-1 and BS-5 are much more similar to each other than to an anti-azobenzoate L chain (Appella et al., 1973), from which they differ by 30 and 29 residues respectively. Of these interchanges 13–15 are confined to the three hypervariable sections, and 11 occur within the N-terminal 27 positions. The three chains have an identical sequence from residue 98 to residue 139, except for a possible inversion of two residues in positions 130–131 of the anti-azobenzoate chain.

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