Protein

Protein motif

Motifs are short continuous sequences associated with differences in the function of a protein. The analysis of the motive protein sequences of the endoglucanase gene coding for B. subtilis , showed the presence of the dominant CBM3 motif that represents the binding activity of the cellulose substrate by enzymes. Other short motifs were also found along the protein sequence ( Figure 13 View Fig 13 ), including ASN_Glycosylation, camp_phospho_site, CK2_phospho_site, myristyl, and PKC_phospho_site, as studied in B. subtilis from rice brain (Jannah et al. 2019) [ 20].

The ASN_Glycosylation motive is a post-translational modification (glycosylation) area in the residual aspargin (ASN) area. The CAMP_phospho_site motif shows the area of phosphorylation using cAMP or cGMP, and the CK2_phospho_site motif shows the area where casein kinase II phosphorylation occurs (Deihimi et al. 2012) [ 28]. and is found in the amino acid sequences STKD, TTVD, and tyle ( Figure 10A View Fig 10 ). The myristyl motif shows the site where the myristylation process is the addition of a myristyl group to a protein at the end of the translation process (Maurer-Stroh et al. 2002) [ 29]. and is found in the amino acid sequences GTSDAS, GASKTG, GTKDST, GSMNSN and GASTGN ( Figure 10A View Fig 10 ).The PKC_phospho_site motif shows the area where the phosphorylation of protein kinase C occurs (Leonard et al. 2011) [ 30]. and is found in the amino acid sequences SDK, STK, TAR, TYK, TLK ( Figure 10A View Fig 10 ).

Tracing the motives on the protein sequences of the endoglucanase gene coding for B. thuringiensis from the sample of Sargassum sp. shows the protein motif GH8 ( Figure 12A; 12B View Fig 12 )). This motif has been identified as a characteristic feature of the glycohydrolase group of enzymes. Other short motifs were also found along the protein sequence, including the ASN_glycosylation motif, the camp_phospho_site motif in the amino acid sequence KRES, the CK2_phospho_site motif in the amino acid sequence SYYD, SATD, SSLD and SGWD, the MYRISTYL motif in the amino acid sequence GTSEGQ, GMIITV, GSNGTV, GIKASN and GSNIGS and the PKC_phospho_site motif in the amino acid sequence SVR, TAR, TFK, SKK, SNK, and SDK ( Figure 12A View Fig 12 ; 14 View Fig 14 ). Based on In silico analysis of the endoglucanase gene protein sequences in B. subtilis and B. thuringiensis from samples of Eucheuma sp. and Sargassum sp. It can be seen that the two protein sequences have endoglucanase enzyme functional activity of the two bacterial isolates. The protein motives of the two endoglucanase gene sequences are similar, which indicates a close gene relationship between the two Bacillus strains.The catalytic and cellulose binding domains of B. subtilis were GH5 and CBM3, whereas those of B. thuriengiensis were GH8, and no substrate binding domains were found ( Table 8).