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Comparative biochemical analysis of three members of the Schistosoma mansoni TAL family: Differences in ion and drug binding properties.

Thomas CM, Fitzsimmons CM, Dunne DW, Timson DJ - Biochimie (2014)

Bottom Line: The tegumental allergen-like (TAL) proteins from Schistosoma mansoni are part of a family of calcium binding proteins found only in parasitic flatworms.Despite the presence of two EF-hand-like structures in SmTAL3, neither was predicted to be functional.Overall, these data suggest that the proteins have different biochemical properties and thus, most likely, different in vivo functions.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL, UK; Institute for Global Food Security, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, UK.

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EF-hands from the SmTAL proteins. Molecular models of the EF-hand sequences from each of the SmTAL proteins are shown. In each case the potential ion coordinating residues are shown. For SmTAL1 both EF-hands are shown occupied by a calcium ion. In SmTAL2 only the second EF-hand is shown occupied and in SmTAL3 neither is shown occupied. These calcium ion occupancies are consistent with predictions based on the structure and sequences, and with the experimental data presented in this paper (see Results and Discussion).
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fig1: EF-hands from the SmTAL proteins. Molecular models of the EF-hand sequences from each of the SmTAL proteins are shown. In each case the potential ion coordinating residues are shown. For SmTAL1 both EF-hands are shown occupied by a calcium ion. In SmTAL2 only the second EF-hand is shown occupied and in SmTAL3 neither is shown occupied. These calcium ion occupancies are consistent with predictions based on the structure and sequences, and with the experimental data presented in this paper (see Results and Discussion).

Mentions: In SmTAL1, both EF-hands are folded into the typical loop (Fig. 1). In the first motif, the potentially coordinating residues conform to the preferred ones, expect at -Y (Met-27, where threonine is preferred). However, this at this position coordination is provided by the backbone oxygen. In the model presented here, this oxygen atom is orientated into the potential ion binding space (Fig. 1). The second EF-hand in SmTAL1 also has the typical structure and this motif has preferred residues at all the potentially coordinating positions. Thus, based on these predictions, both EF-hands have the potential to be functional calcium binding sites (Fig. 1).


Comparative biochemical analysis of three members of the Schistosoma mansoni TAL family: Differences in ion and drug binding properties.

Thomas CM, Fitzsimmons CM, Dunne DW, Timson DJ - Biochimie (2014)

EF-hands from the SmTAL proteins. Molecular models of the EF-hand sequences from each of the SmTAL proteins are shown. In each case the potential ion coordinating residues are shown. For SmTAL1 both EF-hands are shown occupied by a calcium ion. In SmTAL2 only the second EF-hand is shown occupied and in SmTAL3 neither is shown occupied. These calcium ion occupancies are consistent with predictions based on the structure and sequences, and with the experimental data presented in this paper (see Results and Discussion).
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4300400&req=5

fig1: EF-hands from the SmTAL proteins. Molecular models of the EF-hand sequences from each of the SmTAL proteins are shown. In each case the potential ion coordinating residues are shown. For SmTAL1 both EF-hands are shown occupied by a calcium ion. In SmTAL2 only the second EF-hand is shown occupied and in SmTAL3 neither is shown occupied. These calcium ion occupancies are consistent with predictions based on the structure and sequences, and with the experimental data presented in this paper (see Results and Discussion).
Mentions: In SmTAL1, both EF-hands are folded into the typical loop (Fig. 1). In the first motif, the potentially coordinating residues conform to the preferred ones, expect at -Y (Met-27, where threonine is preferred). However, this at this position coordination is provided by the backbone oxygen. In the model presented here, this oxygen atom is orientated into the potential ion binding space (Fig. 1). The second EF-hand in SmTAL1 also has the typical structure and this motif has preferred residues at all the potentially coordinating positions. Thus, based on these predictions, both EF-hands have the potential to be functional calcium binding sites (Fig. 1).

Bottom Line: The tegumental allergen-like (TAL) proteins from Schistosoma mansoni are part of a family of calcium binding proteins found only in parasitic flatworms.Despite the presence of two EF-hand-like structures in SmTAL3, neither was predicted to be functional.Overall, these data suggest that the proteins have different biochemical properties and thus, most likely, different in vivo functions.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL, UK; Institute for Global Food Security, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, UK.

Show MeSH