In protein structure, STRIDE (Structural identification) is an algorithm for the assignment of protein secondary structure elements given the atomic coordinates of the protein, as defined by X-ray crystallography, protein NMR, or another protein structure determination method. In addition to the hydrogen bond criteria used by the more common DSSP algorithm, the STRIDE assignment criteria also include dihedral angle potentials. As such, its criteria for defining individual secondary structures are more complex than those of DSSP. The STRIDE energy function contains a hydrogen-bond term containing a Lennard-Jones-like 8-6 distance-dependent potential and two angular dependence factors reflecting the planarity of the optimized hydrogen bond geometry. The criteria for individual secondary structural elements, which are divided into the same groups as those reported by DSSP, also contain statistical probability factors derived from empirical examinations of solved structures with visually assigned secondary structure elements extracted from the Protein Data Bank.

Stride or STRIDE may refer to:

• STRIDE (security), spoofing, tampering, repudiation, information disclosure, denial of service, elevation of privilege
• Stride of an array, in computer programming
• Stride scheduling, a soft real-time scheduling algorithm
• System to Retrieve Information from Drug Evidence, a United States Drug Enforcement Administration database used to track the prices of drugs obtained in sting operations
• STRIDE, an algorithm for identifying secondary structures in proteins